CELL
PHYSIOLOGY BIOLOGY 580
PROFESSOR MARY
LEE SPARLING
BIOLOGY
DEPARTMENT
TABLE OF CONTENTS
WHAT TO USE
IF YOU WANT TO TEST THE EFFECT OF SALT.
HOW TO TEST
FOR INVOLVEMENT OF CA++
WHAT TO DO
TO TEST THE EFFECT OF METABOLISM
HOW TO TEST
EFFECT OF HYDROGEN BONDS
HOW TO TEST
FOR EFFECTS OF PHOSPHORYLATION
TO TEST FOR
MEMBRANE INVOLVEMENT
HOW TO TEST
FOR NUCLEAR INVOLVEMENT
HOW TO TEST
FOR -SH INVOLVEMENT OR REDOX POTENTIAL.
TECHNIQUES
USED TO TEST CHANGE
ERROR
ANALYSIS FOR BIOLOGY 580 LAB I.
PREPARATION
OF PROTEIN SOLUTION DILUTIONS
ARTIFICIAL
ACTIVATION BY A23187 AND PAF
Procedure
for Labeling DNA using DAPI
DETERGENT
EXTRACTION OF MEMBRANES AND PARTICLES.
PROTOPLASMIC
STREAMING IN PLANTS
DESIGN OF
ENDOCYTOSIS EXPERIMENT
SUPERPRECIPITATION
OF ACTOMYOSIN
ACTIN
POLYMERIZATION AS DETECTED BY DNAase INHIBITION
NA+K+ATPASE
FROM MEMBRANES OF SEA URCHIN EGGS
Cell Physiology Lab 2004 Mary Lee Sparling This is a list of possible experiments. We may change the order according to availability of material, or we may decide to do individual projects in place of some of these.
Feb 2 INTRODUCTION-what do we want out of this lab? How well do we make solutions?
4 PROTEIN TEST-PREPARE STANDARD CURVES FOR USE ALL SEMESTER
9 PHOSPHATE TEST
11 FERTILIZATION OF SEA URCHIN EGGS AND DRUGS WHICH ARTIFICIALLY ACTIVATE OR PREVENT FERTILIZATION
13 Last day to drop class without approval
16 MEMBRANE PHOSPHOLIPASES AS DETECTED BY TLC
18 SECRETION, ENDOCYTOSIS
20 last day to add class
23 CELL MOTILITY;SLIDING FILAMENTS:TRADESCANTIA AND ELODEA
25 MEMBRANE Preparation, use of detergents
March 1 ACETYLCHOLINESTERASE
3 CILIA AND FLAGELLA, motors and microtubules
8 turn in lab books, try to set up microelectrodes setup
10 INHIBITORY SYNAPSES AND DRUGS SPECIFICITY AT DIFFERENT SYNAPSES
15 GLYCOLYTIC ENZYME CONTROL BY HORMONES AND ENERGY CHARGE
17 PURIFICATION OF TUBULIN FROM CHICK BRAIN
22 PCR or DETECTION OF MRNA
24 DRUGS WHICH EFFECT DIVISION
29 MEIOSIS BLOCKS IN EGGS AND THEIR RELEASE TO COMPLETE MEIOSIS
31 holiday
April 5-10 spring break
12 FISH SCALE PIGMENT MOTILITY
14 PURIFICATION OF MYOSIN AND ACTIN. TURN IN LAB BOOKS.
19 MYOSIN ATPASE
21 ELECTROPHORESIS
26 ELECTROPHORESIS STAIN AND INTERPRETATION
28 ANTIGEN-ANTIBODY INTERACTION- OUCHTERLONY AND ELISA
May 3 REGENERATION PLANERIA, EFFECT OF RETINOIC ACID, DRUGS
5 CELL INTERACTIONS- LONGTERM-MORPHOGENS, INDUCTION
10 APOPTOSIS CONTROL AND PREVENTION
12 ACTIN ASSEMBLY
17 CANCER, WHAT CONTROL IS LOST IN ONCOGENES?
19 last day-CLEAN UP LAB AND FINISH LAB BOOKS Prepare poster of best experiments.
1. We can assemble
some systems to try working with artificial membranes and single cell
microelectrodes.
2. We can purify
some proteins. We can use centrifugation, columns, and salt extraction.
(myosin, tubulin, actin, Na+K+ATPase)
3. We can do
electrophoresis and Western blot with antibody detection of proteins
4. We can observe
cell motility, organelle motility in cells and effects of drugs and salts.
5. We can do
membrane lipid purification and analysis
6. We can study
cell cycle and drugs which modify it in sea urchin eggs. We can do
immunohistochemical detection with antibodies.
7. We can study
protein kinases and phosphatases.
8. We can do
protein and phosphate tests and standard curves.
THE WAY THINGS ARE CHANGED IN CELL PHYSIOLOGY LAB
We used to do experiments where we did not know
how they were supposed to come out, then we tried to explain our results. We
were given the hypothesis to test, we were given the chemicals, and we were
given directions of how to do an experiment.
Now we are given a topic, let's say "How
does cytoplasm move? " We are given an idea of available equipment,
reagents, animals or plants. Then we are told- observe something about cell
movement or at least something to do with cytoskeleton.
Decide how
a certain system can be used to test an hypothesis: for example,
1. A sea urchin sperm can only
enter an egg if both of them can polymerize an available supply of G-actin.
Then you can test various ways to prevent actin polymerization to see if it
prevents fertilization. You would have to do a library search using let's say:
su:actin polymerization fertilization prevention or acrosome pH Calcium osmotic
pressure. So instead of figuring out what 1M glycerol does, you would figure
out what it might do before you use it- why do you use that instead of salt?
2. pollen cannot germinate without the assembly
of actin ( test in the presence of cytochalasin or colchicine or metabolic
inhibitors.)
3. pollen cannot germinate without first altering
the pollen coat, and the continual softening of the advancing cell wall tip (in
the presence of a protease inhibitor or a cellulase inhibitor or a protein
kinase inhibitor or EDTA)
4. Elodea chloroplasts can move around on an
actin sheet in the presence of ATP and Ca++. Then you have to figure out how to
cover a slide with actin filaments.
5.
Substitute equal osmotic material that does not
ionize- glycerol, sucrose, urea, ficol.
Change the concentration, or substitute divalent
for monvalent, or K or Li for Na.
Add EDTA or EGTD to tie up divalent cations.
Use sephadex to change ionic medium.
Use ion exchange chromatography and elute with
different salts to see which has an effect.
Use ionophores.
Change ratio of monovalent and divalent ions.
Precipitate with ammonium sulfate- salting out.
Precipitate by dilution- myosin.
Use A23187.
Add EDTA or EGTA or citrate to chelate it.
Inject it.
Add Ca++ pump poison.
Poison Ca++ channels
Add inhibitors of glycolysis or CAC or ETS.
Cut off O2 supply.
Cut off CO2 supply for plants
Remove light for plants.
Remove food.
Uncouple oxidative phosphorylation
HOW TO TEST
THE EFFECT OF WATER- use heavy water or
carbowax to cut down amount of water in cell.
Use glycerol to cut down water concentration.
Break bonds with urea or heat. With actin
and tubulin, depolymerize with cold.
FIND A
SPECIFIC DRUG THAT PREVENTS AN ACTION
Then try different concentrations or time of application.
To TEST FOR
EFFECT OF PH. Carefully prepare buffers
of different pH, or apply materials which alter internal pH like ammonium
chloride.
Use amiloride to prevent H/Na exchange
HOW TO TEST
FOR ACTION OF ATP OR G PROTEIN OR SECOND MESSENGERS:
Look up
specific inhibitors of these in reactions. There is a handbook on inhibitors in
the library. Vanadate effects ATP-utilizing proteins , inhibits phosphatase.
Test for increases or decreases of P-amino acids.
Test effects of cAMP, cGMP, ATP, GTP in presence
of permeator molecule such as digitonin.
Lead can trap phosphate broken off molecules,
then be made black to observe.
Use detergents, Triton-X, digitonin, ionophores.
Extract with chloroform-methanol.
Use centrifugation to pellet membranes to see if
material soluble at certain times, attached at others.
Make membrane vesicles, isolate, turn inside out,
see effect.
Teat for endocytosis of material, exocytosis
prevention or initiation.
Get temperature effects due to lipid phase
change.
Change salt gradients. Add channel poisons,
change charge across membrane with voltage clamp.
Add actinomycinD to prevent RNA synthesis,
puromycin to prevent protein synthesis
Use many poisons, one at a time.
Precipitate out protein with TCA,
Test Q10 of reaction to see if just diffusion or
if enzyme.\
Use DTT, mercaptoethanol, diamide,
centrifugation
thin layer chromatography
gas-liquid chromatography
electrophoresis
observation in microscope
antibody reaction for immunocytochemistry or gel
detection
immunodiffusion plates
enzyme assay
spectrophotometric detection by wavelength
column chromatography
gel filtration
microelectrodes, voltage clamp
cell injection
image analysis
fixation, sectioning and staining
dialysis
salting out
alcohol precipitation
lipid extraction
fluorescence detection
drug treatment
milipore filtration
detergent extraction
high salt extraction
microdissection
isoelectric focusing
recombinant dna
reporter genes
make models or cell-free systems such as tubulin
or actin on a slide with motors moving over them
affinity chromatography
hydrophobic chromatography
cell ph or ion concetration detection by dyes or
microelectrodes specific to one ion
fluorescent or other analogue chemistry
TO PURIFY A
PROTEIN, need a way to follow it
through the procedure and to detect presence of contaminants:
enzyme assay, electrophoresis, antibody,
radioactivity
INDIVIDUAL PROJECTS CAN BE SUBSTITUTED FOR STANDARD LAB WORK.
INTRODUCTION
This cell
physiology lab is designed to do several things:
1. Acquaint you with biological experimentation as a non-exact science
2. reinforce your knowledge of the experimental method, force you to start out
each experiment with an hypothesis to test, make you aware of the importance of
control experiments for comparison;
3. Allow you to think of cell activities as products of control of the
cytoskeleton, secretory and endocytotic mechanisms, and metabolic machinery
which can result from nuclear or environmental stimuli which produce
alterations in membrane structure or other changes which can result in ionic
concentration differences or enzymatic alterations. Our most common
experimental variables will be temperature, calcium and magnesium ion
concentration, cytoskeletal disruptors, metabolic inhibitors and substrate
concentration, and anesthetics that alter the membrane.
4. Allow you to learn some of the methods used in biological research in cell
physiology. This will be a great advantage to those going into graduate work,
or teaching, or professional school. Not very many universities have courses in
cell physiology. That is why I had to write this manual, so you are fortunate
to be able to have this opportunity as an undergraduate.
Occasionally we have labs which do not produce the expected results of the
hypothesis. The common error of students is to think that these labs failed. It
is just as important to your education in biological research to figure out why
some experiments do not "work out" the way they were expected, as it
is to get beautiful results. Most of research is spent getting the experimental
conditions to the point where data can be collected and meaningful results
collected. Research is not cookbook chemistry, and I have not attempted to
write a cookbook. I have taken some experiments from the literature and tried
to adapt them to classroom application. There are often time constraints, which
make this difficult. Sometimes, we try a different species due to availability.
Sometimes experimental animals die right before the class, sometimes mistakes
in solution making can occur, since graduate students often are also doing this
for the first time, and sometimes the lab temperature is very warm or very cold
which can change rates of egg development, or cell motility.
No lab should be considered wasted, since you will learn to handle volumetric
measurement, microscopic proficiency, quantitation, methods for handling
proteins, enzymes, live cells. If you are consistently getting nonsensical
results when everyone else is not, then you must ask for help. You may have bad
pipetting methods, solution labeling methods, glassware washing methods, or
data recording technique.
You can help
insure good lab technique by the following:
1. Purchase a glass marking pen, some graph paper, a cheap stopwatch, and keep
them in your backpack.
2. Take good notes during the experiment about any variation of technique and
record your results accurately. You can save yourself enormous amounts of lab
time by setting up tables ahead of time for filling in the
results.
3. Read about the experiment in your text and any references in the lab manual
before you come to the lab. You will get much more out of the experiment. You
should write some of the possible conclusions to such experiments before you do
them. For example, if you are going to vary the ion concentration in a certain
enzyme test, find out what that ion does in cells, in relation to that enzyme
so that you will have a possible explanation of your results. You will not be
able to figure out what your experiments mean unless you do this. You may want
to bring your texts to class as resource books, or your biochemistry text may
also help. If the experiment involves cytoskeletal disruptors, find out what
each one does, and write it in your lab book, since that can be referred to
many times. Since you always have to turn in your lab results at the end of the
week, you must have some of the work done before the lab.
4. Don’t rely on the instructor to tell you what this experiment is supposed to
mean. I will be happy to answer questions, but I expect you to do some work
before you come. It is not always possible to coordinate the lecture with the
lab, so sometimes you will do something in lab we have not yet discussed in
lecture. Therefore, you will have to read in your text to find out where it
fits in the overall cell physiology. That reading will just make it easier when
we come to that part in lecture.
5. Always use clean glassware. Most of the time you can see
dirt in glassware. You will not have a problem if you always leave it clean at
the end of the lab, to dry for the next time. Always take clean pipettes from
stock for the day, and then put them back at sink to be washed at the end of
the day. Glassware should be immersed in hot soapy water and brushed
individually, then rinsed eight times in running tap water and three times in
distilled water. Invert to dry. Disposable pipette tips and cover glasses need
not be washed.
6. Keep your lab exercises after they have been graded. Your lab book will be
handed in at the end of the semester for review and grade. The lab assistant
will grade some experiments, but the instructor will make the final analysis.
Do work with your lab partners, but write up your experiments by yourself,
since they will be compared at the end. That is where the prelab work will show
up. Don’t copy material from books or articles without referencing them.
Looking topics up on the web of on your text CD is also a great idea.
SOME LAB TIPS
PIPETTING. For good control of the pipette use your index finger on the tip of
the pipette, not your thumb if using the blue bulbs. Pull fluid up into the
pipette until slightly above the place where you want the volume to be. Release
your BULB at the same time as you place you finger on the tip. If the tip of the
pipette is wet, you will not be able to easily release a part of the volume to
get it to the volume you wish to deliver, so don't have wet fingers. Probably
the most accurate way to pipette is by the blowout method, where you only take
up the amount you wish to release, each time you place a volume in a tube, then
blow out the fluid using the bulb after it flows to a stop. With the black
bulbs, always make sure you remove the cotton from the pipette, and for small
volumes don’t have a high vacuum on the bulb or you will suck fluid into the
bulb. Always use the size pipette near the volume you want (use a 1 ml for
.1-1, use a 5ml for 1.1-5, a 10 ml for 5.1-10.0. Each time you pipette, you
magnify the error. Don't use large pipettes for small amounts to deliver,
because you cannot read the large diameter as accurately as the smaller
diameter pipettes. For amounts less than .1 ml use the automatic pipettes with
disposable tips. During the same lab, you can use the same tips, if you label
them by marking them with a marker to prevent contamination of the reagents.
For all materials use rubber bulbs. Most lab chemicals are not toxic, but by
law we cannot mouth pipette.
DILUTIONS. To make dilutions, divide the desired concentration by the present
concentration, and then use that value to determine the desired volume of
concentrated reagent to dilute with water to the final volume.
Example: reagent prepared is 1 M. Reagent concentration desired in
your reaction mixture is 6 mM or .006M. Divide .006 by 1= .006. You need 25 ml
of reaction mixture, so multiply 25 by .006= .15 ml you need to add before
bringing the mixture to a final volume of 25 ml. Often in making reaction
mixtures you have to add several reagents, so add up all the reagent volumes
added, subtract from the 25 ml, then make up the difference by adding water. Bringing
a calculator to lab is essential. IT IS IMPORTANT NOT TO DILUTE
REAGENTS TO THE FINAL CONCENTRATION DESIRED BEFORE ADDING THEM TO THE REACTION
MIXTURE BECAUSE THAT WOULD DILUTE THEM FURTHER.
pH. The pH of reactions is very important and must be controlled during
experiments. Make sure that all reagents are the proper pH, and then add buffer
at the controlled pH desired. Usually, use 0.01M or less final concentration.
SPECTROPHOTOMETERS.
Always check to be sure the filter system is correct for the wavelength you
wish to use. Then turn it on 20 min before you need to use it, so it can
stabilize. Use only special tubes, and insert them so the markings are at the
front. Make sure you know how to zero the instrument, and have a control tube
for doing that.
WATER
BATHS. Fill the water bath with water the approximate temperature you want, and
then adjust it with ice and a thermometer. For heat, use warm water, then turn
on the heating element and adjust it so the light just comes on at the desired
temperature, and goes off when you turn it a little bit lower. Then watch it
for a few minutes, to be sure it is right.
REAGENTS.
Since the whole class has to use the reagents, it is important that dirty
pipettes not contaminate them. Take the amount of reagent you have figured out
that you need for the whole day, placing it in an Erlenmeyer flask, well
marked. Since there are 16-20 students and 8-10 pairs of partners, never take
more than 1/10 of the total volume. At the end of the day, you can put back
reagent that you feel is uncontaminated, particularly expensive ones like ATP,
cytoskeletal disruptors, protein standard reagents, phosphate standard
reagents, GTP, buffer, sucrose. Always keep high-energy compounds like ATP,
GTP, G6P, acetylcholine, or proteins isolated from cells on ice during the
day since they break down at room temperature. Never add them to your reaction
mix until the last minute.
ABSENCES.
There will be two absences allowed, with library work to makeup labs. Habitual
tardiness, or long coffee breaks, or allowing your lab partner to do the work,
is always noted by the instructor and will be reflected in your final grade.
GRADING will be subjective. An A grade will be for those who do the work, write
the reports, including drawing correct conclusions about the experiments. This
will include getting results on unknown samples given by the instructor. To be
able to do all of this in 3 hours takes organization, done largely before
coming to lab. The instructor will do spot checks to see if you have done your
prelab work. It is possible for everyone in lab to get an A, if everyone does
the work well.
REFERENCES FOR
LABORATORY EXPERIMENTS RESERVE ROOM SOUTH LIBRARY
UNDER SPARLING,
BIO580L
Dynamic Models
in Biochemistry. A workbook of computer simulations using electronic
spreadsheets. D.E. Atkinson, S.G. Clarke, D.C. Rees. Benjamin/Cummings Publ.
Co.
Mathematical
Models in Plant Physiology. J.H.M. Thornley. Academic Press. 1976
Analytical
Chemistry G.D. Christian 1986
Physical methods
on biological membranes and their model systems. F. Conti,
WE Blumberg, J. de Geir, F. Pocchiari . Plenum Press.
1982. Reaction
Quantitative
Analysis by gas chromatography. J. Novak. M. Dekkar, N.Y. 1975.
Mathematical
Models in Plant Physiology. JHM Thornley. Academic Press 1976.
Data reduction
and error analysis for physical sciences. PR Bevington. McGraw Hill 1969.
GET NEW LIST
FROM INSTRUCTOR
How
can one evaluate the expected error for an experiment? Break
up this answer into parts:
1.
figure out the expected error for each step in the
test See Analytical
Chemistry by Christian.
A.
Purity of chemicals: analytical reagents are 99.95%
pure B. Weighing:
the last digit of the scale gives the
sensitivity analytical
balance to .1 mg,
larger scale to .1 g or .01g (see scale)
so the accuracy depends upon the amount weighed since .1 g is a lot less of the
total weight when you have 30g than when you have .3 g total.
C.
Pipettes: blowout two rings around
top
10 ml error .02
5 ml .01
1 ml .006
automatic pipettes to 1‑2% or .01-.02
D.
Volumetric glassware:
100-1000 ml volumetric flask .0003
graduated cylinders .01
To
calculate the expected error in your experiments you use these values X
the total you are using (g,ml) and that squared gives you the variance
for what you really measure out- expected error.
E.
calculate the total error‑ all the errors combined, some of which
may cancel out others by adding up all the variance (error
squared.)
See Taylor, or Christian, or Bevington, or Freund
We
will do this on a spreadsheet where you will enter
1) the proper expected error from the list above, and the amount measured
(ml,g) and it will automatically give you the expected error which will
then be squared to give you variance for that sample or solution in the
columns so marked. Then in the end, you will get the total for each sample in
the standard curve or enzyme analysis.
2) When you are doing a standard curve you have more than one sample, so you
have to multiply the total variance by the number of samples to get the
total variance for the test.
3) to get the expected error for the test, which includes getting the
regression line and equation, you take the square root of the total variance.
What is the difference between accuracy and precision? The accuracy of a test
is just what we were just talking about, but the precision is a matter of how
repeatable your results are.
What is the difference between standard deviation and
variance? How can variance be used to
determine the total error in additive
tests?
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c.
Regression analysis of linear expressions We
will do a regression analysis of our standard curves. Today we will enter data
and do regression. same references
These
would be the errors expected from volumetric and weight errors. There are
left instrumental errors (usually .01) and operational errors. How can one
control for that?
COMPUTER ANALYSIS OF DATA FOR 580L
We
will use the apple computers to do regression analysis and statistics on our
protein curves, phosphate curves, and enzyme activity curves.
First we will enter our data into a spread sheet, using Cricket.
The
IBM can be used for Excel spreadsheets.
LIST
OF CHEMICALS AND MOLECULAR WEIGHTS
chemical
VOL MW desired conc
standard
sodium phosphate
NaH2PO4:H2O
138
PO4 1
L 31 10ugPi/ml
trichloracetic
acid
TCA
500 ml
5%
Phosphate
detection reagents:
1)
sulfuric acid
5N 141ml conc/l titrate to
check
sodium molybdate
500 ml-
18.76g in 2.5N H2SO4
2)
stannous chloride stock solution 40% 25ml in conc HCl
use diluted .25 ml/50 ml H2O
protein
detection reagents:
3)
sodium
carbonate
1 L 2% in 0.1 M NaOH
sodium
hydroxide
MW=40
4)
sodiumpotassium tartrate 100 ml
1%
5)
copper
sulfate
100 ml .5%
6)
solution A- 48 ml soln 3 +1ml soln 4+ 1ml soln 5
7)
std bovine serum
albumin 150
ml 1mg/ml
8)
Folin phenol reagent dilute 1/2
Buffers:
tris
buffer pH
8.0 50
ml 121.14 1M
CALCULATIONS:
Figure
out the weights or measures for all the solutions needed.
Then
using the spreadsheet figure out the expected error in such solutions and in
the protein test and phosphate test by entering the error for each part of
making the solution or test:
protein test. Look at the reagents for protein detection test above. Figure out
whether you use the balance, pipettes, what kind of glassware to see the
possible error. If you have a good calculator, you can use that instead of the
computer.
For reagent 3 you first make the three solutions, then you combine them. Then
you use 5 ml (pipette) for each sample.
so you will use a 1 liter volumetric, weigh out the sodium carbonate and sodium
hydroxide and bring the volume to 1 l. Then the solutions 4,5 are made in 100
ml volumetric flasks, and you pipette out 1 ml of each. Now add up all the
possible errors for all these processes by getting the variance and then
summing them. Now try the whole thing using graduated cylinders instead of
volumtric flasks, and see the difference in the expected error. Record your
results in your lab book.
Find out how much difference it makes to use a 5 ml pipette for pipetting 1 ml,
compared of using a 1 ml one.
So
what you need is a worksheet which has kind of measure in the first column, the
known error for the step in the second column, the amount measured in the 3rd,
column 2 x 3 to give the measurement error at this step in col 4; col 5 has
this value squared and this is the variance.
read the
introduction and lab clues.
Start out by
thinking to yourself: "What is the purpose of doing a standard curve for
protein?"
How does one prepare a standard curve from data? What is the purpose of having
duplicate samples?
Answer in brief: When we have a preparation of protein with unknown protein
content and we want to know how much is there, we can use this test if we have
a standard curve from which we can calculate how much protein is there from the
amount of blue color detected. When we have duplicates, there is leeway for an
occasional mistake such as a dirty tube or a dropped tube or pipetting error
since we can average values or throw out tubes that are obviously wrong.
MATERIALS TO
HAVE CLEAN AND READY: 30 testubes, testube rack, pipettes, 100 ml graduated
cylinder. Marking pencil (bring your own felttip marker to lab from now
on.) You may work with one lab partner, but make sure that you each do
part of the pipetting and dilution. We will use the black rubber bulbs
for these experiments for the pipetting. Let the air out the top by squeezing
the two top buttons together. Let the fluid in to the level you want by squeezing
the two bottom buttons right above the pipette that say S (Suction). To let the
fluid out place the tip of the pipette on the side of the vessel, above the
fluid level and press the two buttons together marked E (empty). To get out the
last little bit cover the tip of the small rubber bulb with a finger and
squeeze the small bulb while holding the S buttons open. We get better curves
with regular pipettes than we get with automatic pipettes, since there is
difficulty getting used to automatic pipettes so that consistent samples are
taken.
Preparation of
solutions
REAGENTS: Solutions may contain more than
one chemical. The Reagent A contains four things which are not stable when
mixed, so they are mixed each day from solutions which are stable.
reagent A
1%NaK TARTRATE
2cc
0.5%CuSO4
2cc
mix these two,
in a 100 ml graduated cylinder,then add
2% Na2CO3 in 0.1N NaOH TO MAKE A TOTAL OF 100ML
the solution
must be used the same day. 100ml will
be enough for 19 samples.
reagent B Folin phenol
reagent (0.5cc per sample x number of samples)
add an equal quantity of distilled
water
Example: 5cc
Folin reagent + 5 cc water will be enough for 19 samples- you never can recover
all of a solution.
Bovine serum
albumin: If the BSA
stock solution you need is supposed to be 1 mg/ml but the one provided is 0.1
g/ml (100 mg/ml) dilute it 1/100 (since you don't need 100 ml, use .5/50ml then
we will have 1000 ug/ml (1 mg/ml) stock solution .
PRELAB
PREPARATION
Standard curves are graphs of optical density (absorbance) versus concentration
of some compound. We are not particularly interested in how the chemical part
of these tests work, we are only interested in learning how to determine
quantitatively how much of various unknown things we have in different cell
fractions or preparations.
For
standard curves to work right we have to have a constant volume of material to
be tested. For the Lowry protein test we used 0.5 ml samples with known amounts
of protein; for the Pi test, we will use 2 cc samples diluted in 1.6 ml TCA. We
must have the approximate proper range of concentrations of material in our
known samples or they will be too dark or too light to make a good curve. For
proteins we should have between 50 and 600 ug/ml for good readings, so we usually
have to dilute a cell fraction preparation 1/5 or 1/10 before testing them
for the Lowry test.
important: you will use this standard curve for the
rest of the semester to figure out how much protein you have in solutions. So
be very careful; do a good job, or you will have to repeat it.
Now you are going to set up two sets of tubes: if possible use different racks
for 1 and 2.
one set of dilutions of BSA each with a
volume of 2 ml, these will be used to make up the second set;
All
measurements should be as accurate as possible, with graduated pipettes for
amounts under 10 ml and graduated cylinders for larger quantities.
label 7 tubes with the concentrations in
the left column below and make these
combinations. This will
be your first set of dilutions in rack one.
BSA DESIRED CONC STOCK |
AMOUNT 1000uG/ml BSA |
AMOUNT distilled water |
600 uG/ml |
1.2 ml |
0.8 ml |
500 |
1.0 |
1.0 |
400 |
0.8 |
1.2 |
300 |
0.6 |
1.4 |
200 |
0.4 |
1.6 |
100 |
0.2 |
1.8 |
50 |
0.1 |
1.9 |
set up sets of duplicate tubes, one set
behind the other in the second rack, marked for those same dilutions: you will
take duplicate 0.5 ml samples of each dilution from rack one to be pipetted to
each duplicate two tubes in rack 2. Set up a single water blank tube.
PREPARE
7 PAIRS OF TUBES LABELLED WITH THE DILUTION AND ONE TUBE FOR THE WATER BLANK.
Take 0.5 ml of the firdt set of dilutions with their known concentration
of bovine serum albumin (BSA) and place in each of the paired tubes (do this in
duplicate, two samples per concentration using labeled tubes) as listed above,)
This will be rack 2.
plus one water blank 0.5 ml) in rack 2.
Don't make the common mistake of using plain water as the final water blank!
The water blank is .5 ml water plus all the reagents used in the test.
Keep the first rack dilution set
separate now so you don't get mixed up and use them for the color test. You can
set these away, now, but save them for the Biorad test.
STUDENTS OFTEN
USE THE WRONG SET OF TUBES TO DO THE FINAL TEST. MARK THEM WELL. KEEP THOSE
DILUTIONS in rack 1 FOR THE BIORAD TEST.
You will also be given 2 unknowns with
numbers on them which will tell us which are the correct answers to the
quantity in the unknown. Prepare 0.5 ml duplicates of unknowns, mark tubes.
You must warm up the spectrophotometer
now for 30 min as you do the rest of the experiment. Turn on with left
knob. Make sure you have one with a red filter and red tube.
WARNING!!!!!FOR THE NEXT STEP Mix
each tube swiftly, energetically right after adding each reagent or
the proper color will not develop. Do not wait and mix all after adding all. I you have a lab partner, one person
should pipette, one stir. Get a demonstration of how to stir tubes from the
instructor.
ALWAYS START WITH THE WATER BLANK Add 5
ml of reagent A to all
of the tubes in rack 2 containing the .5 ml aliquots, SINCE YOU WILL USE
THAT FIRST TO ZERO THE SPECTROPHOTOMETER.
Mark down the time. Wait ten minutes after all additions,
mixing. At this step you will have 14 BSA tubes and one water blank and 4
unknowns.
Add 0.5ml reagent B (already diluted with water) mix very
thoroughly, immediately after adding to each tube, rapidly,
Note the time you finish, wait 30
minutes. Read at 650 nm on spectrophotometer. Zero the instrument without
the cuvette using the left knob, for the left side of the scale with the blank
tube out (0.5 ml water plus all the reagents). Then set at 0 absorbance
with the right knob for the right side of the scale, using that water
blank in the cuvette. Read the unknowns and knowns starting from the lowest
concentration, pouring each into the same cuvette, shaking out excess
from the cuvette after pouring samples back. Read duplicates one right after
the other without changing the settings of the spectrophotometer. Make
sure the densitometer is set at the proper wavelength and has a red filter in
place. Wipe the tubes with tissue before inserting them in the well. There is a
mark on the front of the tube so they are inserted correctly. Make sure you use
the proper cuvettes for reading the optical density.
Record your data on the lab sheet that
will be turned in at the end of the lab. Data includes all values, not just the
averages of the duplicates.
Make a table of the original data using
Cricket or other computer program. Average the two values for each known
concentration. 4. Plot the optical density versus the protein concentration in
ug/ml using the computer. Do not divide by two even though you only used 0.5 ml
in your test, and later when you use this on an unknown you will not have to
worry about multiplying by 2 to get the concentration in ug/ml. However, when
you use less than .5 ml for your unknown tests in later experiments, and then
add water for dilution to make up the rest, you will have to take that into
account in your unknown, multiplying by the dilution, in that .5 ml.
You should get a
fairly straight line with a little dropping off at the top of the curve.
Compare your results with others in the lab.
Prepare a permanent lab book for the
semester and place these results into it after they are graded. You
should always bring your lab book to lab and put your results directly into the
book from now on. Also bring a disc for the MAC to record your data. You will
use some of these results in later experiments. Do not loan your results to
anyone else, unless given permission by the instructor. That will be considered
cheating by both people.
Everyone is allowed to miss two labs or
throw out the lowest score. Other missed labs will be counted as zeros. To get
credit for a lab you must attend the whole lab period, unless you finish early.
You should always read the experiment before you come to class.
Clean your glassware with dilute soap
(too much soap is hard to get off), 8 rinses with tap water and 3 rinses in
distilled water. Set upside down to drain before next lab period.
In cases where
we use many tubes, such as today, we will use the dishwasher. Place tubes
upside down in dishwasher racks.
This assay is for samples which are not very dilute. Use the Lowry test for
dilute solutions
1. Prepare dye
reagent. IT TAKES AT LEAST HALF AN HOUR TO FILTER THE REAGENT SO DO IT
EARLY. It is supplied as a 5x concentrate. Dilute 1/5 (1+4), stir and
filter through #1 filter paper. This lasts for 2 weeks in a dark bottle in
refrig.
Prepare standards for a standard curve
with Labeled tubes. You can use the dilutions from the Lowry test you
already made. Make dilutions of unknowns so that they may be in this range (it
is usually safe to do a 1/10,1/50 dilution of cell homogenates), this means
there will be 200 to 1400 ug/ml. YOU CAN USE YOUR STANDARD DILUTIONS FROM THE
LOWRY TEST, except for the dilutions below 200 ug/ml
Place .1 ml of each into marked duplicate
pairs of tubes. Prepare a water blank of the same volume.
Add 5 ml diluted dye reagent to each
tube. Vortex or mix, but avoid foaming.
Measure OD at 595 nm (with water blank
(plus biorad reagent) adjusted to 0, ) after 5 minutes or up to an hour.
Plot OD versus concentration for the standards,
plot in Cricket to get the equation and then read your unknown concentration
and multiply by the dilution for the final concentration.
THE
SPECTROPHOTOMETER IN THIS CASE DOES NOT USE A RED FILTER OR TUBE. CHECK TO MAKE
SURE THEY ARE NOT PRESENT. THIS STANDARD CURVE WILL BE USED FOR THE REST OF THE
SEMESTER. BE CAREFUL.
For the Pi
test, we want between .2 and 7 ug/ml of standard or unknown phosphate. We
will use NaH2PO4:H2O as our standard solution. To get a stock solution of 10
ug/ml or 10 mg/l of P, we know the MW of the whole molecule is 138, and of the
P is 31, therefore 31/138=.01/x= .045g/l of NaH2PO4 will
contain 0.01 g/l P. That will be our stock solution.
MAKE TWO RACK AS
WE DID LAST TIME- ONE FOR DILUTIONS, DUPLICATES IN SECOND.
TO MAKE THE
DILUTIONS OF THE STOCK SOLUTIONS:
TUBE
MARKING
|
ML
STOCK
|
ML
H2O
|
P CONC ug/ml |
10 ug/ml |
|
0 BLANK |
0 |
5 |
0.2 |
.1 |
4.9 |
0.4 |
.2 |
4.8 |
0.6 |
.3 |
4.7 |
0.8 |
.4 |
4.6 |
1.0 |
.5 |
4.5 |
2.0 |
1 |
4 |
3.0 |
1.5 |
3.5 |
4.0 |
2 |
3 |
5.0 |
2.5 |
2.5 |
6. |
3 |
2 |
YOU HAVE PREPARED 11 TUBES WITH DIFFERENT
DILUTIONS.
We will now prepare PAIRS, two SEPARATE
duplicates, EXCEPT FOR THE WATER BLANK. 1 ml samples from each of these
dilutions, a total of 21 tubes, to be used directly to test for color
development.
To each of the 1 ml samples, add 1 ml of
5% TCA to each tube for a total of 2 ml.
Then to each tube add 1.6 ml sodium
molybdate
Shake immediately, if not sooner.
Dilute fresh each day .25 ml Stannous
Chloride in concentrated HCl reagent (just let reagent run into pipette and
then let it run out until it is at the .75 on a 1 ml pipette, then blow it out
into a 50 ml graduate cylinder, fill to 50 ml with H2O. Be careful not to
contaminate this reagent with a pipette containing P (detergent has lots of P).
Add 0.4 ml of this diluted reagent to
each tube, but only do a few tubes at a time, because they must be read 2
minutes later
Plot curves
using Cricket, store data on disc.
PREPARATION
AND MATERIALS PER GROUP OF FOUR STUDENTS:two sea urchins, syringe, 2 small
beakers (50 ml), filtered sea water, ph 5,7,8 sea water, CA++Mg++free sea
water, hand centrifuge, container of ice.
THIS INVESTIGATION REQUIRES: SLIDES and
coverslips ANIMALS:sea urchins
(Echinodermata) UTENSILS:50 ml beakers, syringe
and needle for injection of sea urchins, centrifuge tubes, pipettes, petri
plates.
PRELAB;
LOOK UP FERTILIZIN, ANTIFERTILIZIN, BINDIN, VITELLINE MEMBRANE, SPERM MOTILITY,
ACROSOME REACTION, CORTICAL REACTION.
OBJECTIVES:
to see sperm movement, attachment to egg, lifting away of fertilization
membrane from surface of egg, first cleavage and to investigate mechanisms
involved.
REQUIRED
TASKS: fertilize eggs, observe fertilization membrane lifting off the surface
of egg.
OBSERVE
EFFECTS OF PH, TEMPERATURE, CA++ CONTENT ON FERTILIZATION. TEST THE EFFECTS OF ‑SH
AGENTS ON FERTILIZATION MEMBRANE HARDENING. Students to work in pairs and turn
in completed lab sheet at the end of the lab
PROCEDURES:
In this section you will determine the relationship between eggs and sperm and
correct environmental conditions required for normal fertilization,
fertilization membrane formation, and first cleavage LABEL ALL
DISHES OF EGG FERTILIZED WITH THE TIME OF SPERM ADDITION, AND ANY VARIABLE
CONDITION. MAKE SURE YOU HAVE AN UNTREATED CONTROL WHICH HAS NO SPERM ADDED, IF
THAT IS REQUIRED IN YOUR EXPERIMENT.
EACH GROUP OF 2 STUDENTS;
1.inject two sea urchins
with 1 cc of .55 M KCl and then give them a good shake and wait to see what sex
they are: the gametes come out five gonopores at the aboral surface (opposite
the oral surface where the mouth is) if the gametes are white, it is sperm and
should be shed by turning the male upside down in a petri dish placed on ice;
if the gametes are yellow, it is a female and the eggs should be shed into
filtered sea water (pH 8) by inverting them over a beaker full of sea water.
The beaker should be of smaller diameter than the sea urchin so that it won't
fall in. Keep injecting until you get both sexes, after appropriate waits to
see what the next one is. You can trade with other groups, also.
ALWAYS KEEP THE EGGS AT ROOM TEMPERATURE AND THE SPERM ON ICE This means use
room temperature sea water in all egg treatments and at fertilization. If it is
cold, warm it by setting it in a pan of warm water. Give another 1 cc
injection when egg spawning slows down, then leave the female to complete the
spawning for about ten more minutes. In the meantime, design your experiments
and label your dishes.
After spawning is
complete pour off the sea water into another beaker, so you don't lose your
eggs by mistake. Pour the remainder into a centrifuge tube and spin 15
rotations on the hand centrifuge (make sure you have a balance tube opposite.)
REMOVAL OF EGGS FROM THE CENTRIFUGE TUBES CAN DAMAGE THEM UNLESS IT IS DONE
CORRECTLY! Always pour some fluid over the eggs, then using a pasteur pipette
with a rubber bulb, fill the pipette with fluid from the top of the tube, then
gently force the fluid out into the bottom of the tube to stir the eggs. Do not
let air bubbles do the stirring, and don't creat air bubbles or suck the eggs
up into the pipette and then back out‑ it homogenizes them.
Removal
of jelly: Add 25 ml ph5 sea water to empty the eggs from the tube into the
beaker, and allow it to stand for three minutes before adding .5 ml 1 M tris pH
8 to raise the pH rapidly. (the pH 5 treatment removes the egg jelly, but
prolonged treatment leads to damage to the eggs.) Now we must remove the
dissolved egg jelly by washing the eggs. So do centrifugations as above, SAVING
THE FIRST SUPERNATE, LABEL IT JELLY, and wash the eggs with a tube full of sea
water pH 8, 2 times, suspending the eggs each time as above.
Now we have our eggs prepared for the experiment. Sperm are much more delicate than the eggs, so they must be kept undiluted in ice (the seminal fluid has substances in it to keep the sperm inactive and the ice also helps to do that.) They must be diluted prior to their addition to the eggs, or we get polyspermy and abnormal cleavage. Add one drop of concentrated sperm to 10 cc of sea water in a graduated cylinder, stir to disperse evenly. This diluted sperm suspension will only last for 20 minutes, so do it right before you need it, and keep it in the ice bath. Prepare a slide with a drop of eggs, have it set up on a microscope prior to seprm addition adjusting the light the eggs on the slide easily visible. Add a drop of the sperm, slam the cover slip on the slide and place under the low power objective and observe fertilization. If you don't get fertilization try it again with another batch of sperm from someone who found good fertilization. Then proceed to fertilize your aliquots of eggs.
Fertilization: ADD 0.1 ML
DILUTED SPERM TO 10 ML OF SEA WATER CONTAINING .1 ML EGGS. Observe, using dissection
microscope and dark field (obtained by putting mirror on its side until field
appears black and eggs appear white) or compound microscope. The
fertilization membrane is formed by a lifting away of the vitelline membrane,
and an addition of material to it from the ruptured and released contents of
the cortical granules. Look at the number of sperm around one egg,
record for a few eggs. Observe and record the sperm shape and size compared to
the egg, movement of the flagellum.
For polyspermy, get one dish of eggs with about 100 sperm per egg. Check the
effect on cleavage, as compared to the control.
Test the effect
of pH on fertilization. Fertilize a DISH of eggs in the same manner, but use pH
5 sea water in one dish, pH 7 in another. Record the % fertilization membranes
formed after 1 min, 5 min. What is your control?
IF YOU ARE GOING TO CULTURE THE EMBRYOS TO LATER STAGES, DECANT OFF THE SPERM
LADEN SEA WATER ATER THEY SETTLE, AND POUR A SHALLOW LAYER INTO PYREX BAKING
DISHES AND INCUBATE THEM AT 15 DEGREES C FOR ANYTHING PAST THE 2 CELL STAGE OR
THE CLEAVAGES WILL NOT BE SYNCHRONOUS. IT TAKES ABOUT 1 1/2 HRS TO GET TO THE
FIRST CLEAVAGE. KEEP CHECKING TO SEE IF YOU CAN SEE THE MITOTIC APPARATUS
DEVELOPING. The fertilization membrane is formed by a lifting away of the
vitelline membrane, and an addition of material to it from the ruptured and
released contents of the cortical granules. Look at the number of
sperm around one egg, record for a few eggs. Observe and record the sperm shape
and size compared to the egg, movement of the flagellum. What is your control?
Why is the lifting of the fertilization membrane a good indication that a sperm
has penetrated the egg?
If you are going to culture the embryos to later stages, decant off the sperm
laden sea water after they settle, and pour a shallow layer into pyrex baking
dishes and incubate them at 15 degrees c for anything past the 2 cell stage or
the cleavages will not be synchronous. It takes about 1 1/2 hrs to get to
the first cleavage. Keep checking to see if you can see the mitotic apparatus
developing.
Keep in mind that we have two sets of factors working in fertilization: 1) the
activation of the sperm acrosome reaction, polymerization of actin filament 2)
activation of egg and cortical reaction. Try to figure out which require Ca++
release and which require a pH change. Calcium ionophore and NH4 can be used to
answer these questions.
reference-Nucciteli:
How do sperm activate eggs? Current topics in developmental biology vol 25.
Chapter 1. 1991.
EFFECT OF TEMPERATURE ON
FERTILIZATION. Fertilize
a dish of eggs that has been sitting on ice for ten minutes. Compare the
percent fertilization after and 5 min. with the control. .UL EFFECT OF
CA++ ON FERTILIZATION. Fertilize a dish of eggs using Ca++Mg++free sea water
instead of regular sea water. Compare the results with the control.
EFFECT
OF ‑SH REAGENTS ON VITELLINE MEMBRANE AND FERTILIZATION MEMBRANE. treat the eggs with DTT or glutathione
prior to fertilization, and check them after addition of sperm.
METHODS FOR REMOVING VITELLINE MEMBRANE:
1. Epel, D., AM
Weaver, D. Mazia. 1970. Exp cell res 61:64-68. Methods for removal of the
vitelline membrane of sea urchin eggs. I. Use of Dithiothreitol (Cleland Reagent.)
Incubate
unfertilized S. purp or L. Pictus or Dendraster excentricus in 5 mM DTT at pH
8.0. Releases jelly, and vitelline m and accessory cells of starfish. 5 min to
remove jelly and VM. pH very important. higher pH (9.2) requires 1/2 the time.
2. BM Shapiro.
1981. Awakening of the invertebrate egg at fertilization. In Fertilization
and embryonic development in vitro. Eds. L Mastroianni, Jr. and JD Biggers.
Plenum Press, NY. pp233-255.
used 3
amino-1,2,4-triazole to inhibit ovoperoxidase activity, FM remains soft and can
be removed anytime (Showman and Foerder, 1979:Exp Cell Res. 120:253-255.
Removal of the fertilization membrane of sea urchin embryos employing
aminotriazole.)
3. SG Ernst, BR
Hough-Evans, RJ Britten, and EH Davidson. 1980. Limited complexity of the RNA
in micromeres of sixteen-cell sea urchin embryos. Devel. Biol. 79:119-127.
fert at 5x10 E5
eggs/ml add equal vol of following after membrane elevates (about 90
sec):freshly prepared .08% papain, .40%glutathione, pH 7.8, swirl gently and
look until membranes begin to disappear 90-120 sec later. After 7-9 min dilute
to 1-3x10 E4.
4. RO Hynes and PR
Gross. 1970. A method for separating cells from early sea urchin embryos.
Devel. Biol. 21:383-402.
fert eggs in 0.04%
papain, .2% cysteine, sea water, pH 7.8. Make fresh daily. Keep eggs suspended
4-5 min, spin down gently, remove supernate, wash 2x with filtered SW
What do these
methods tell us about how the vitelline membrane is held on the egg and what
happens at fertilization to lift it off as the fertilization membrane?
PLATELET-ACTIVATING FACTOR CAN ACTIVATE THE CORTICAL REACTION IN SEA URCHIN UNFERTILIZED EGGS AND MEIOSIS IN STARFISH EGGS
Mary Lee
Sparling, Biology Dept Jan, 2001
Platelet-activating
factor (PAF) is a choline phospholipid similar to phosphatidyl-choline, a
membrane lipid, but having an acetyl group on its second carbon instead of a
long acyl hydrocarbon chain. It causes secretion of materials stored in
secretory granules in many kinds of cells (blood platelets, neurons, immune
cells, and follicle cells) and causes the acrosome reaction of sperm. The
effect of PAF is due to a PAF-receptor which when occupied can cause activation
of many enzymes producing lipid second messengers or lipid substrates. PAF is a
very ancient and important lipid signal in reproduction and may aid gamete
union as well as prevent apoptosis of egg and sperm once they are united since
PAF Receptor can activate PLA, PLC, PLD, PI3K, GTPase, Ca++ channel, and
PKC. Production of PIP2 by PI3K or activation of PKC, to phosphorylate
many cell proteins, prevents apoptosis. PAF is produced after fertilization by
sea urchin egg homogenates and after stimulation of meiosis in starfish egg
homogenates. It is considered an autocoid, or substance that when secreted can
cause changes to the cell that produced it. Fluorescent PAF and other related
lipids (LPAF, PC, PE) were applied to eggs to see where they go. The effect of
PAF does not seem to require entry into the cell. Application of 5X10-4
M PAF caused secretion of the cortical granules which usually only occurs in
eggs which have been fertilized. A similar activation of secretion can be
caused by calcium ionophore A23187 which also activates the enzyme pathway
which synthesizes PAF. Normal PAF production at the time of fertilization may
be the cause of the secretion of the acrosome by sperm and the cortical
reaction in normal eggs, and a part of the program for activation of cell
division and differentiation.
take .2 ml
eggs, add following add all to tube before eggs except sperm
|
20ul |
|
1ul |
1ul |
1ul |
20ul |
|
5ul
|
|
|
sperm |
|
alc |
PAF 10-3M |
PC 10-3M |
HEPES |
|
BSA .1% |
|
E1 |
|
|
|
|
|
|
|
|
|
row
1 |
x |
|
|
|
|
|
|
|
do first to
check |
row 2 |
x |
|
x |
|
|
x |
|
x |
control for
second |
row 3 |
|
|
x |
|
|
x |
|
x |
|
row 4 |
|
|
x |
|
x |
x |
|
x |
|
row 5 |
|
|
x |
x |
|
x |
|
x |
|
row 6 |
x |
|
x |
|
x |
x |
|
x |
do second to
check |
|
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Database:
MEDLINE
Author(s): Brandriff B ; Hinegardner RI ; Steinhardt R
Title: Development and life cycle of the parthenogenetically activated sea
urchin embryo.
Source: J Exp Zool (JOURNAL OF EXPERIMENTAL ZOOLOGY) 1975
Apr; 192 (1): 13-24 Journal Code: I47
Abstract: A method is reported for inducing parthenogenetic development in eggs
of the sea urchin Lytechinus pictus, a species which previously could not be
artificially activated. NH4OH or the calcium ionophore A23187 are
used as activating agents followed by hypertonic treatment. The
ionophore is superior in activating large numbers of unfertilized
eggs, whereas NH4OH produces a larger percent of embryos able to undergo
gastrulation. Both feeding larvae and urchins arising from
these artificially activated eggs are diploid. All individuals
in which sex has been identified have
been
female. The viability of these completely homozygous organisms is low
compared to their
fertilized counterparts.
Author(s): Kamata Y ; Mita M ; Fujiwara A
; Tojo T ; Takano
J ; Ide A ; Yasumasu I
Address: Department of Biology, School of
Education, Waseda University, Tokyo, Japan.
Title: Probable participation of phospholipase A2 reaction in the process of
fertilization-induced activation of sea urchin eggs.
Source: Dev Growth Differ (DEVELOPMENT GROWTH AND
DIFFERENTIATION) 1997 Aug; 39 (4): 419-28 Journal
Abstract: In sea urchin eggs activated by sperm,
A23187 or melittin, BPB (4-bromophenacyl bromide, a phospholipase A2 inhibitor)
blocked fertilization envelope formation and transient
CN(-)-insensitive respiration in a concentration-dependent
manner. BPB had virtually no effect on the increase in [Ca2+]i (cytosolic
Ca2+ level), the activity of phosphorylase a and the rate of
protein synthesis, as well as acid production and augmentation
of CN(-)-sensitive respiration. BPB also inhibited
fertilization envelope formation and augmentation of CN(-)-insensitive
respiration induced by
melittin.
Melittin, known to be an activator of phospholipase A2, induced the
envelope formation,
acid
production, augmentation of CN(-)-insensitive and sensitive
respiration, but did not cause any
increase
in [Ca2+]i, the phosphorylase a activity and the rate of protein
synthesis. An activation of
phospholipase A2
induced by Ca2+ or melittin seems to result in cortical vesicle
discharge and
production of
fatty acids, which are to be utilized in CN(-)-insensitive lipid
peroxidase reactions.
Activation of other examined cell functions in eggs activated by sperm or
A23187, probably results from Ca(2+)-triggered sequential reactions other
than Ca(2+)-caused activation of phospholipase A2.
Author(s): Elhai J ; Scandella CJ
Title: Arachidonic acid and other fatty acids inhibit secretion from sea
urchin eggs.
Source: Exp Cell Res (EXPERIMENTAL CELL RESEARCH) 1983 Oct;
148 (1): 63-71 Journal Code: EPB
Abstract: Massive secretion at the egg surface follows fertilization of sea
urchin eggs or parthenogenetic activation by the calcium ionophore
A23187. The secretory products are used to construct the
fertilization envelope around the egg. Arachidonic acid prevents the
raising of the fertilization envelope induced by either sperm
or A23187. We developed a secretion assay based on the ability of A23187
to raise fertilization envelopes from the surface of unfertilized eggs.
Arachidonate delays the onset of this reaction in a dose-dependent
fashion. 5 microM arachidonate produces a two-fold delay in the
standard assay. In contrast, the propagation of secretion over the
surface of the
egg is
unaffected at all concentrations that have been tested. Some closely
related fatty acids (e.g.
11, 14, 17 C20:3
and linoleate, 9, 12 C18:2) share with arachidonate the ability to
inhibit
secretion,
whereas others (e.g., 8, 11, 14 C20:3 and linolenate, 9, 12, 15 C18:3) do
not. The results are not easily reconciled with a cyclooxygenase- or a
lipoxygenase-mediated action. Despite the sensitivity of this
phenomenon to small changes in fatty acid structure, it is suggested that
the fatty acids exert their effect by altering the structure or dynamics
of the membrane lipid bilayer.
Database: MEDLINE
Author(s): Chambers EL ; Hinkley RE
Title: Non-propagated cortical reactions induced by the
divalent ionophore A23187 in eggs of the sea urchin, Lytechinus variegatus.
Source: Exp Cell Res (EXPERIMENTAL CELL RESEARCH) 1979 Dec;
124 (2): 441-6 Journal Code: EPB
Both of these experiments described in Foerder et
al Proc Natl Acad Sci 75:3183-87.1978.
This assay will
take advantage of the transphosphatidylation by the enzyme, taking choline off
PC and putting the ethanol on it as a head group. The Ptd Eth can be detected
on TLC. REFERENCES: D. Zoukhri, DA Dartt. 1995. Cholinergic activation of PLD
in lacrimal gland acini is independent of PKC and calcium. Am. J Physiol 269 (3
pt1);c713-20.
Ella, KM, Dolan,
JW, Meier, KE. 1995. Characterization of a regulated form of PLD in the yeast S.
Cerevisiae. Biochem. J. 307;799-805.
SPRECIFIC
EXPERIMENT
Change in
phospholipases at fertilization of sea urchin eggs.
NEED: SEA URCHIN
EGGS AND SPERM, If continuing from the previous fertilization lab
start at the ***#4 below
SEA WATER, pH 8,
HOMOGENIZING MEDIUM:(100 mM KCl, 5 mM MgCl2, 1 mM ATP, 10 mM benzamidine, 25 mM
tris Cl pH 9.6), (Need 50 ml)
ETHANOL,
DETERGENT- octylglucoside
PLD reaction mix: (one with and and one without 2% ethanol)
150 mM NaCl
25 mM HEPES pH 7
5 mM EDTA
1 MM EGTA
1 mM DTT
10 mM substrate such as PC sonified in 200uM octylglucoside (make 10x, 2 ml)
(Triton-x inhibits enzyme, as does freezing)
ethanol or not
Each group needs 4
ml. (20 ml total of solution.)
1. shed sea urchin gametes into sea water by .6M KCl (in class had 15 ml eggs.
treat with pH 5 3 min, adjust to pH 8 with tris, settle, then add new sea water
so each group has 15 ml diluted eggs.) Take out 30 ml for unfert with and
without Ca++.
2. fertilize the rest, (add .1 ml diluted sperm per 10 ml) check to see if
membrane lift away, place on ice at a timed interval, like 5 min to stop
development after
3. spin 15 ml in hand centrifuge to pellet eggs, measure volume ( about 1.5 ml
each),
****4.homogenize both unfert and fert batches using 10 ml homog medium, keep
cold. spin 20,000 rpm 10 min to get the membrane pellet.
5. place each pellet (fert and unfert) in 2 ml PLD reaction mixture and
homogenize. KEEP COLD.
REACTION:prepare in
a small eppendorf tube:
40 ul
resuspended pellet with phospholipases
2ul fluorescent PAF in detergent
2 ul ethanol (add last)
add additional things like 1 ul Ca++
This will make a
fluorescent assay possible.
So have a control
with only Plipase, PAF, place in
tube,label well CONTROL. You should have one for the unfert, one for the fert.;
place a control with Plipase, PAF, ethanol in a different tube and mark
ETHANOL, one for fert, one for unfert, and an experimental with Ca++, Plipase,
PAF, ethanol in a different tube for both fert and unfert, mark Ca++. Now warm
them up!
7. Incub in white incubator for 20-30 min at 35 degrees.
place 5 ul of
sample on G60 silica gel plates (no Fluor marker)
Develop plate:
chlor:meth:water/aCETIC ACID (45;45:10;1
PHOTO UNDER LONG
WAVE UV WITH plate reader
Measures peroxide production-eggs at
fertilization or macrophages
Requires: scopoletin to be oxidized 10 uM added
10 s after HRP, dissolved in DMSO, so DMSO final conc is 7mM
3-amino-1,2,4-triazole to inhibit ovoperoxidase
horseradish peroxidase Type II 1.7 ng/ml added 10 s after fertilization
catalase
method of Root et al. J Clin Invest
55:945-955.1975
scolpoletin loses its
fluorescence when oxidized by HRP and H2O2. 5mM procaine which blocks granule
release inhibits oxidation of scop. 24% without eggs in presence of H2O2, but
completely with eggs
fert eggs 1-2% suspension, after 10 s add HRP,
after another 10 s add scopoletin, swirl, take 2.7ml aliquots at intervals-
like every min through 15 min. Add aliqouts to .3ml 100 mM NaCN in SW pH8 to
stop oxidation. Spin 1000g 10 min 4degrees, decant super and read in
fluorometer excit 350nm, monitor 460nm
Chemiluminescence: use scintillation counter
eggs 1-2% vol/vol settled eggs/SW, incubate with
sperm in 1:1000 dilution in scintillation vials 15 degrees in shaking water
bath. Remove vials at intervals to count chemiluminescence- see Rosen and
Klabanoff J Clin Invest 58:50-60. 1976.
Can try with A23187, NH4. Ionophore chemilum is
delayed. Inhibited by triazole.
Reference: Spector, D., Goldman, R. Leinwand,
L. (1998). Cells-A Laboratory Manual: Subcellular Localization of Genes
and Their Products. volume 3. p. 101.10
Labeling
Fixed Cells
1. Prepare a
stock solution at 10 mg/ml of DAPI (m.w. 350) in distilled H20, protect
from light, and store at 40C.
Prepare a 5000-fold dilution in PBS to be used for labeling.
2. Prepare a fresh
3.7% formaldehyde solution for fixation. Also prepare a 0.2% Triton
x-100 solution of permeabilization.
3. Aspirate the
cell medium.
4. Rinse cells
three times with PBS (+).
5. Fix the cells
for 10 minutes in 3.7% formaldehyde solution.
6. Aspirate and
rinse the cells three times for five minutes each in TBS
7. Permeabilize
the cells by immersion in 0.2% Triton X-100 for five minutes.
8. Aspirate and
rinse three times for five minutes each in TBS.
9. Incubate the cells at room temperature for 1-5 minutes in the DAPI labeling
solution.
-Preparation for DAPI solution: 1ul in 5ml of distilled water
-add 1ml to each tube and let sit for 1-5 minutes.
10. Aspirate off
the labeling medium, rinse at least once in TBS and
mount.
-Observe under microscope using UV lighting.
We will use the
extracted supernates and pellets to analyze how effective each detergent is in
extraction. We will do the analysis of proteins by electrophoresis and lipids
by TLC and GC. Read about the effect of detergent in your texts. Detergents
form a hydrophilic coat on the outside of membrane proteins hydrophobic
regions. Both molecules are aphipathic, so the hydrophilic part is facing
outside to the water. Membranes are formed because the hydrophobic portions of
the proteins and lipids intertwine as a bilayer, but the detergent can disperse
them. The detergent concnetration is very important because there is a critical
micelle concentration which is the concentration when little bubbles of
detergent with the hydrophobic portion is facing inward. The detergent replaces
the lipid around the protein, dissolving them from the membrane. Ionic
detergents bind to the proteins and lipids in such a way as to disrupt ionic
and hydrogen bonds, often denaturing the protein. For example SDS binds to
every side chain of proteins. Nonionic detergents such as Triton-X, lubrol,
octylglucoside form mixed micelles at high concentrations (above critical
micelle concentration) containing lipid, protein and detergent. At low
concentration they bind to proteins hydrophobic regions allowing them to remain
unaggregated during purification and dissolving them from membranes.
Find the critical micelle concentration (CMC) at room temperature for the
detergents available:
Triton-X,
zwittergent,
octyl-glucopyranocide
(contain alkyl group),
lubrol,
SDS,
tween-20
deoxycholate
We will want to
try 2 concentrations of each, one 2X above, one 2x below CMC. The low
concentration will probably extract peripheral proteins, the high the integral
ones.
What kind of
control do we need to run?
Calculate the
amount of detergent to weigh out for these concentrations in 10 ml. Use
the molecular weights in the Sigma chart.
We will homogenize tissue -1 gram- in 4 ml detergent (or any weight with 4x
detergent volume/wt). Should there be salt or buffer present? The CMC varies
with buffer. Temperature is also important since some detergents form a gel in
the cold. We usually start the process on ice to prevent denaturation by
proteolysis or lipolysis. Adding EDTA can prevent metalloproteases from breaking
down the proteins once extracted.
Will the kind of
homogenizer matter? Since detergents are foaming, the waring blendor approach
is not so good.
Design your
experiment. Think about what equipment you need. For example tubes, centrifuge,
what speed, pipettes, balance
Folsch extraction membranes, whole eggs, isolated mitotic apparatus,
cortical hulls, sperm, can all be extracted with chloroform:methanol
Have a
source of the fatty acid, either on TLC gel scraped off plate, or evaporated or
powder.
1. add 3 ml 5% methanolic HCl.
2. heat in teflon capped (tightly closed) tube for 2
3. add 3 ml pentane, shake on vortex stirrer for at least 30 sec, spin for 5
min, remove the pentane from the bottom to a new tube, add 2 ml pentane to
original tube and repeat the extraction, combine pentane with the first
pentane.
4. Add 1 ml water to the pentane, shake and remove water from the bottom (this
should remove any non
???
TLC. place a 10 ul sample on two marked tlc plates.
Place other samples on the same plate. Be sure to place a standard mixture on
each plate, one of neutral and one of polar lipids. Develop the set with
neutral lipids (set the plate into a container with 80 ml petroleum ether, 20
ml ether, 1 ml conc acetic acid) and it will approach the scribe at the top in
about 30 minutes. Develop one for polar lipids ( container has 64 ml
chloroform, 25 ml methanol, 10.5 Ml acetic acid.) This will take up to an hour
to develop. Keep the top tightly closed to make it go evenly. Remove from
the container and place in a hood to dry. Spray with detectors or pour over the
gel 3% Cu acetate in 8.5% Phosphoric acid (concentrated is 85%). Heat in a
preheated oven at 140 degrees for 30 min. Remove and store in the dark covered
by foil until you can look at the spots. Otherwise, decide the relative
darkness of the various spots in each sample and between samples.
Alternates
lipids can be treated with various phospholipases before being analyzed.
Read about
protoplasmic streaming before coming to class http://www.cells.de/cellseng/medienarchiv/index/3_funk.htm
http://www.cells.de/cellseng/medienarchiv/archiv/bp1c1562d/1562_b11.htm
http://www.cells.de/cellseng/medienarchiv/archiv/bp1c1562d/1562_b19.htm
Work in groups
of TWO. Organisms to be used are plants: TRADESCANTIA AND
ELODEA which have been exposed to light for an hour before use
place a stamen of Tradescantia (the male part of the flower) or a leaf
of Elodea torn to expose some thinner layers on a slide and observe. See
which has the best streaming and then prepare 10 duplicates. Keep them wet with
water. Observe all slides to make sure they are alive before doing any experiment.
Keep them under a light, but don't get them hot or dry them out by having them
too close.
Effect of vital
stains:
immerse the Tradescantia stamen or Elodea leaves in 0.05% Vital stains by
dropping some stain on the slide. Observe whether there is a difference in the
staining by :
Methylene blue
Neutral
red
Janus green b.
Are the
particles stained so that you can see them moving? In the unstained control can
you see any particles moving? Which ever one does the best, use it for the
other experiments so that it is the easiest to see the particles moving.
Effect of
amino acids on movement
effect of histidine 10 mg/ml in 0.05M tris buffer. Observe the movement after
placing one drop on a drained preparation (use a piece of filter paper to drain
off any soluions when it says replace fluid.) If there is an effect, add
water until it goes back to normal.
Effect of
temperature on movement
place one slide on ice and leave for 15 minutes before observing movement, then
observe immediately and as it warms up. Effect of light on movement:
place one
slide in your cabinet with foil around it (make sure you had water on the prep)
and observe after 1 hr.
Effect of pH drain a prep and then add water
buffered to pH 8.3 And observe movement. See if you can quantitate the
rate. Drain the preparation and replace fluid with pH 5.8, Doing that
twice to wash away the pH 8. Observe and quantitate, repeat at pH 7.
Effect
of anesthetics add a drop of 2% methanol, 2% ethanol, other alcohols
and observe movement.
Effect of
cytoskeletal disruptors
these agents are expensive, so take only what you need, or bring back what you
don't use. Look up the effects of these drugs on cells before coming to
lab.
Using
Cytochalasin in 4% DMSO. A control here
must be 4%DMSO alone.
Colchicine 1uM
VINBLASTINE 1 mG/mL
EGTA .1mM
CaCl2 10uM add 3 drops
ATP 2 x 10 -3 M
caffeine
References:
annual review plant physiology 25:309
How do you
explain the effects of vital dyes, histidine, and cytoskeletal disruptors?
How are
microfilaments or microtubules involved in the movement? What kinds of motors
are present in plants to move cell particles?
These two experiments are done together with the
idea of relating them in terms of mechanisms of protoplasmic movement.
Ref: Rapid germination of pollen in vitro.
D.J. Schimpf. The American Biology Teacher 54:168-9. 1992.
Germination solution: 10 g sucrose, .01 g boric
acid, .03g calcium nitrate in 100 ml distilled water. This is GS.
Dust the pollen powder over the bottom of a tiny
disposable plastic petri dish (best results occur when there is oxygen, not
under a coverslip.) Replace cover, and label. Add a few drops of one of the
solutions and observe under 10x, and when germination starts, take out a sample
and place on a slide with a coverslip so you can look at it with 40x. It is
important to get Impatiens flowers with colored anthers at the center of the
flower, not a green solid structure. If you want to study the difference
between immature and mature pollen you can use the anthers from an unopened bud,
and try to see what will make it germinate.
Some pollen germinates in 5-10 minutes, continues
to lengthen for an hour. Others germinate after an hour. Be sure to write down
the time you placed the pollen in solution. After seeing the germination in your
control pollen, pick the flowers which worked the best, and continue the rest
of the experiment, but also do Tradescantia since that will be used in the
second half of the experiment.
CAN YOU MAKE AN HYPOTHESIS ABOUT WHAT CAUSES
POLLEN GERMINATION?
Pollen lands many
places, but the only place where it will do any good is on the stigma of the
ovary. There a sugary secretion is sticky and holds it on the surface, and then
after germination, the pollen grains digest their way through the tissues of the
style, perhaps using the digestion products as an energy source, until reaching
the egg where the sperm nuclei move from the pollen tube to fertilize it in
preparation for seed formation. NEXT: TEST YOUR HYPOTHESIS.
Prepare the control as above, in the germination
solution. Also try some experimental dishes to get at the signaling mechanism
and the outgrowth mechanism. The following solutions can be used:
1. GS without sucrose
2. GS without Calcium
3. GS without boric acid
4. Chelating solution: .35M sucrose, .001 M EDTA,
HEPES pH 7.2 (EDTA BINDS CALCIUM SO IT IS NOT AVAILABLE)
5. calcium ionophore A23187 makes channels in the
membrane so calcium can enter or leave the cell. 1mg/4ml GS.
6. GS with colchicine 25 uM (.o1 mg/ml)
7. GS with cytochalasin 2.4 mg/ 2ml GS + 4 drops
DMSO
8. .3 M KCL (cells have high K+ inside and low
outside, so the gradient across the membrane which usually determines membrane
potential will be changed.)
9. 1M glycerol (osmotically like sea water)
10. distilled water
11. apple peel in water (ripe apple peel has
ethylene)
12. ammonium chloride solution (alters cell pH)
10 mM (8mg/15 ml GS)
13. peroxide solution, a powerful oxidizing agent
500 uM
14. chlorox solution (dissolves some complex
carbohydrates such as chitin, removing fly egg coats) use 1:1 with water, leave
on only briefly, suck off or dilute with GS.
The following physical factors can also be
tested: cold or hot temperatures; light of different colors by wrapping in
different colors of cellophane; dark; lack of oxygen; bubble oxygen through
solution; bubble carbon dioxide through.
Protoplasmic streaming.
The same samples of pollen tubes can be used for
examination of vesicle transport in white Tradescantia, pigment granule motion
in purple Tradescantia. The purple ones are easier to see, but I could see
movement in all tubes with GS solution, and in hair cells of Tradescantia.
This takes 20x or better yet 40x magnification.
Cell movements usually have an actin filament-myosin
motor combo as in amoeboid movement or tubulin microtubule-dynein or
tubulin-kinesin motor combo as in pigment granule motion or vesicles in
neurons. They have rather opposite optimal conditions. Actin-myosin interaction
requires calcium release to start it and actin can be depolymerized by
cytochalasin or cold. Tubulin-dynein works best at low calcium. Tubulin is
depolymerized by colchicine and cold. Particles are moved toward the center of
the cell by dynein, outward by kinesin. Both kinds of motion require ATP. If
the outgrowth is due to osmotic factors, such as uptake of water, using
different concentrations of sugar, glycerol, salt can test for those effects.
Using the solutions listed on the previous page, do experiments to test which mechanism
might be used here. So all you need to do is take samples from the petri dishes
and make slides to look for streaming in all the experimentals. Always look at
your control first, so you know what to look for in the experimentals.
Discuss the results with your partners. The
object of this exercise is not to have fun and see pollen grow, though we do
allow it. The object is to study protoplasmic motion mechanisms. Gather careful
data. Figure out how best to display it. Can you draw any conclusions? Write
them in your summary report.
EFFECTS OF DRUGS ON
MEMBRANES, CYTOSKELETONS AND THEIR ACTIVITIES
ENDOCYTOSIS
Monensin: inhibits
pinocytosis in rat embryo fibroblasts. Tested by horseradish peroxidase uptake,
and anti-5'nuc-ase antibody uptake inhibition detected after 3 hr, .3 uM for ½
max inhib. Exchange of 5'nucleotidase between cyto organelles and membrane
inhibit 90%. The density
where enzymes found different after monensin. Galatosyl transferase and 5'nuc
increased density from 1.128 to 1.148, and peroxidase taken up in vesicles
changed from 1.194 to 1.160. Alters density of lysosomes and Golgi.
Effect probably due to ionophore effect on Golgi. Inhibits secretion as well.
Wilcox, DK, Kitson, RP
and CC Widnell. 1982 Inhibition of pinocytosis in rat embryo fibroblasts
treated with monensin.Cell Biol 92:859-64
Schroeder,F. Altered phospholipid composition affects
endocytosis in cultured LM fibroblasts. Biochim. Biophys. Acta
649:162-174.1981. the lipid content of membrane regulates amount
of pinocytosis. Phagosome lipid content same as PM, as was ATPase and
5'nuc-ase. However, the quantity of PC is elevated in phagosomes when cells
given choline.
ENDOCYTOSIS
PURPOSE: to see if endocytosis is tied to loss of ATPase, and if prevention of it prevents ATPase loss. We already have seen in our slides that ammonia treated eggs had dark color, never lightened, and ammonia or high pH is supposed to inhibit endocytosis. Also we can try to trigger all secretion granule exocytosis to see if that makes it go away, A23187 did. ATPase can be inhibited by ouabain 10 mM. For activation, A23187 50 ug/ml; ammonium chloride (NH4) 10 mM in sea water, pH 9.0 ( Epel, D., Steinhardt, RA, Humphreys, T, and D. Mazia. (1974) Dev. Biol. 40:245-55).
We can also use cytoskeleton disruptors to
prevent endocytosis. Microtubules involved, so vinblastine 10 uM colchicine should prevent endocytosis since it
disassembles MT. Cold should also prevent. Apply ATPase antibodies to outside
of cell, fertilize, detect antibodies. First we need to see if any stick to
outside, also could try a lawn of cortical granules. In my eggs when I lowered
pH for jelly removal, the stain was dark inside egg, and butyric acid is one
way to artificially activate eggs.
PROBLEMS
1. REMOVAL OF VM, HYALINE, FM
If endocytosis is to be done on UF, as
well, must be removed before fert.
How to tell if really fertilized? Must
keep sample to see if cleaved.
2. HOW LONG TO EXPOSE
Swanson et al, 1985 lucifer
yellow used 1mg/ml, after 5 min punctate stain in cortex, after 1 hr, large
vesicle or in live cells long strands. Detected in microscope, Tri-x film after
3.7% formaldehyde, rinsed, mount in glycerol. Used fluorescein filter set. Cell
viability measured by trypan blue 0.1%. Peroxidase using method with H2O2 and
diansidine.
Used sephadex G25 at pH 5 to measure
bound LY, after triton-x100 8% of it bound to high molecular wt material. PMA-phorbol
ester inc pinocytosis 1.8x.
LY not taken up at 0 degrees
3. DOES FIXATION CHANGE THE INTERNAL CONTENT THAT
WAS TAKEN UP?
in Swanson et al fixed cells (see
above) and did fluorescence
4. How to measure
Microscpoe- correct filters for lucifer
yellow
Dot blot for peroxidase
dextran blue-microscope
Exposure of FM free embryos to Blue dextran at 2 mg/ml in sea water for 20
min to 1 hr
sediment membranes, how
quantitate- absorbance in microcuvette
Fluorescence spectrophotometer- use
.35 ml lysed cells, bring to 1.5 ml Lee and Epel (1983) with acridine
orange.
5. How use NH4 inhibition of endocytosis
add NH4Cl after fert Lee and
Epel (1983) after 2 min, dye turned green, so pH changed- caused 40% efflux of
dye
acetic acid (10 mM potassium acetate
buffer) to pH 6.0 caused loss of dye in 0Na SW
Cells treated with NH4Cl
30-40 mM for 30 min then washed away, lowers pH to 6.5, inhibits coated pit
pathway but not lucifer yellow. (Sandvig et al 1989)
6. Try ruthenium red, heparin to see effect .
Ruthenium red (0.2 mg/ml in sea water for 1 hr in the refrigerator)
used to label cell surfaces in embryos, after FM removal.
7. Victoria blu can be used to see cortical
granules to see if egg fertilized, stain after fixed, so could do fluorescence
of endocytosis, then add victoria blue to same cell to see if truly
fertilized (Schroeder, TE, 1979.) 0.3% alcoholic VB
8. ionophore A23187 used with 0 Na sea water by
Lee and epel (1983) Used 460mM choline Cl and 2.5 mM KHCO3 for
artificial SW to substitute for Na.
9. Sardet,C. 1984 isolated unfert cortex has CG, acidic ves and elaborate ER,
assoc with mito, yolk, acidicves. Plaques on PM where clathrin coats can
assemble for endocytosis after fert. After fert, has coated pits, actin mesh
with acid ves in it
REFERENCES:
Lee, HC and Epel,D. 1983 Changes in intracellular
acidic compartments in sea urchin eggs after activation. Devel. Biol.
98:446-54.
Sandvig, K, Olsnes, S, Peterson, OW and Van
Deurs, B. 1989 Control of coated pit function by cytoplasmic pH. Methods Cell
Biol 32: 365-82.
Sardet,C. 1984 The ultrastructure of the sea urchin egg cortex isolated
before and after fertilization. Dev Biol 105:196-210
Schroeder, TE 1979 Surface area change at
fertilization: resorption of the mosaic membrane. Devel. Biol. 70:306-26.
Swanson, JA, Yirinec, BD and Silverstein, SC.
1985 Phorbol esters and horseradish peroxidase stimulate pinocytosis and
redirect the flow of pinocytosed fluid in macrophages. J. Cell Biol. 100:851-9.
We will
observe the ciliary movement under various conditions, using frog mouth cilia,
planaria and sea urchin blastula stage embryos. Sea urchin blastula can
be prepared by the fertilization exercise and then culture overnight. Gastrula
stage can also be used, and they require 2 days of culture.
Frog
mouth cilia
pith and decapitate a cold frog. Prepare the roof of the mouth for observation
by separating it from the lower jaw. Keep it moist with frog ringers solution.
Cut a very tiny piece of aluminum foil to be carried by the ciliary beat (about
1mm.)
To test effect
of temperature:placing it on ice, recording the surface temperature and the
change in rate. Calculate the Q10. (REMEMBER TO USE RATE, NOT JUST
DISTANCE OR TIME.)
PLANARIA place a planarian in a petri dish and set a lamp next to it. See
which way the planarian moves. Set the lamp in a new position and see how
it moves again. Do this until you develop a hypothesis about how it moves in
relation to light. Now observe its movements in the same solutions used on the
frog mouth. Have an equal amount of test drug and water that the planarian is
in. Make sure that is enough for it to move. Is cordination of the
ciliary movement affected?
Sea
urchin embryos
place
some embryos in 2% ficol
· Materials needed: fish, cold distilled water, applicator sticks, thread, centrifuge bottles and tubes, cheesecloth,filter paper for buchner funnels, 50% glycerol,ice, solutions, meat grinder. Each group of students will need a pan of ice, some cold distilled water, and 60 g of ground muscle. soln A: 0.01M Kcl, 20 mM tris buffer pH 7.4. soln b: 0.45M Kcl, 5mM mercapto-ethanol, 0.2M Mg acetate, 1mM EGTA, 20 mM tris pH6.8. 1 mM NaHCO3 for diluting myosin. 0.1 M ATP. Soln. C 0.5 M KCl, 5 Mm mercaptoethanol , 20 mM tris pH 7.5. soln D: 0.8 M KCL, 5 mM mercaptoethanol, 0.2 M Mg acetate
SOLN A ).01M KCl, .02 M tris pH 7.4 use 1M tris, 1.5 M KCl for one liter 20 ml tris, 6.7 ml Kcl, adjust pH
SOLN B:
500ML
MW
VOL 500
G/L
G/VOL |
.45M KCl,
74.55
33.55
16.77 |
5 mM mercaptoethanol,78.13
.39G
.2ML |
.2M Mg
acetate
214.46
42.9
21.45 |
.02m
TRIS
121.1
2OML 1m 10ML |
.001 M EGTA
380.4
.38G
.19G |
WEIGH OUT ATP TO make
a 50x sln to ADD RIGHT PRIOR TO USE: 605.2 .1M= 60.5MG/ml
OR 605 MG/10ML. Dissolve in tris .001M pH7. adjust add enough to
above soln to make 2 mM |
0.1 mM NaHCO3- MW
84
8.4mg/l
4.2 mg/500ml
SOLN C: 100ml
0.5 M
Kcl
37
.37 mg/ml 3.7
g/100 |
5mM
mercap
40ul/100 |
.o2M tris pH
7.5
2ml |
SOLN D:
100ml
0.8M
Kcl
59.6g/l 5.96 g /100 |
5 mM
mercap
40 ul |
0.2 M Mg
acetate
4.29 g/100 |
0.2M Nahco3
100ml 1.68g/100 |
·
· The fish will be numbed in ice, killed and skinned and the muscle removed from the skeleton and placed on ice except for the long muscle in the back which will be used for glycerinated fibers.
· 1.Each group of 2-3 students should weigh out 20 g of muscle ground in a meat grinder into a beaker.
· 2.Extract this muscle on ice in 10 vol of soln A (200ml): 0.01M Kcl, 20 mM tris buffer pH 7.4. Place in a beaker and keep on ice for ½ hr, This will wash away contaminant proteins, etc. Pour through cheesecloth and throw away the super (unless the muscle disintegrates so not caught on cheescloth in which case you must centrifuge), keep muscle in cheesecloth.
· 3. Place in a beaker (cheesecloth and all) with 5 vol soln B(100 ml): 0.45M Kcl, 5mM mercapto-ethanol, 0.2M Mg acetate, 1mM EGTA, 20 mM tris pH6.8. Add ATP to 2 mM. Incubate on ice for 1 hr. Stir periodically and get muscle loosened from ball but on the cheesecloth. (Ask yourself why we are using ATP and this pH, and EGTA.) Squeeze cloth. Save muscle for step 6. Save liquid for step 4.
· 4. spin down pink liquid in 2 tubes in sorval centrifuge for 15 min at 10,000 g. There are 8 places in the rotor, make sure you balance your tubes on the scale and put them opposite each other, and wait until the rotor is full before running. Save pellet for actin extraction if substantial amount (Step 6), keep pink supernate for myosin purification (sTEP 5.
· 5. Measure volume and Dilute all of the supernate from #4 with cold distilled water 1/25 (add 1 part 10 mM NaHCO3 .) Stand on ice ¼ hr. If you can see the myosin precipitating, suction off the top part which is just cell sol so that there will not be so much to centrifuge. Precipitation cannot occur unless this mixture is at pH 6.5, So measure the pH if you don’t see any precipitate and adjust with 1/20 concentrated acetic acid, making sure you stir well while adding the acid for the adjustment.
· 5. Spin in large bottles in the centrifuge, save the pellet. Dissolve the pellet in 5 cc Soln C;0.5 M KCl, 5 Mm mercaptoethanol , 20 mM tris pH 7.5 by homogenizing in Potter-Elvehjem. Centrifuge at next lab start to remove insoluble material. Further precipitations by dilution and resuspension would further purify it.
· 6.ACTIN PREPARATION reextract the pellet from 3 with 3 volumes of soln D: 0.8 M KCL, 5 mM mercaptoethanol, 0.2 M Mg acetate; 5 min on ice. Centrif 10,000 g for 15 min. Discard super (has more myosin in it)
· weigh and reextract pellet with 2 vol of pellet wt of 2mM NaHCO3 in a beaker for 1 hr on on ice, stir occasionally , centrifuge 48,000g 1 hr discard pellet
We will do light scattering at 540 nm to determine the presence of ppt. To a cuvette containing 0.5 cc of actomyosin add the following in two steps for each set, recording the light scattering change with each.
H20 KCl`
1. 4.5 ML 0
2 2.5 2.5
3. 0 4.5
WHAT IS THE EFFECT OF SALT CONCENTRATION ON SUPERPRECIPITATION? TO LOOK AT THE EFFECT OF CA AND ATP AND MG, SET UP TUBES TO WHICH YOU ADD THE FOLLOWING:
TRIS CA (.01 M) MG(.01 M) MG (.1) CA (.1) H20 EDTA
1. 1 ML .5 ML 3
2. 1 .5 ML 3
3. 1 .5 3
4. 1 .5 ML 3
5. 1 .5 2.5 .5
THEN ADD .5 ML ACTOMYOSIN TO ALL OF THEM AND MIX WITH A PASTEUR PIPETTE AND READ AT 540 NM. THEN ADD A DROP OF ATP TO EACH, MIX AND READ AFTER MIXING. THIS SHOULD BE DONE ON ICE THEN WIPE THE TUBE WITH A WIPETTE JUST PRIOR TO READING. IF YOU LET THE PELLET ALL FALL TO THE BOTTOM OF THE TUBE IT WON'T BE READ, SO THE MIXING IS IMPORTANT. INVERT IF ALL ELSE FAILS. FILL OUT THE ANSWER SHEET. Set these tubes in the refrigerator and look at them next time to measure the volume of the pellet.
ATPASE ACTIVITY DETERMINATION FOR MYOSIN OR ACTOMYOSIN:
1. dilute all myosin to 5 mg/ml by running a lowry protein test to determine the concentration, and then diluting it. If it is less concentrated than that, just note your concentration and use it undiluted.
2. Into a huge test tube prepare the reaction mixture (total vol 25 ml):
2.5 ml 1 M NaCl (final conc after dil=.1M)
2.5 ml 0.2 M TRIS PH 7.5 (final=.02M)
1.25 ml 0.1 M CaCl2 (Final=5 mM)
ul mercaptoethanol (final 5 mM)
13.75 ml H2O
5ml myosin
set this in 25 degree bath for 5 minutes to bring to temperature.
In a separate test tube rack, prepare tubes marked 1-6., add 2 ml of 5% TCA to each tube. You will pipette 2 ml samples from the reaction mix into these tubes at different time intervals. These must be ready before the next step.
Add 2.5 ml ATP to the reaction mixture (not the TCA tubes)and mix well and note time or press stop watch
4. Pipette out your first 2 ml sample as soon as you can to serve as a 0 time blank, but since it will not be zero time, record the time as you pipette it into the TCA. Take four other samples spaced over 30 minutes pipetting each into the TCA and recording the exact time. (It isn't important to get it done exactly at 5 min but it is important to know exactly the number of min and sec passed since adding the ATP to the myosin.)
5. Filter the TCA mixtures into clean tubes.
6. pipette 2 ml of the filtered TCA reaction mix into tubes, marked so you can tell which is which.
7. Add 1.6 ml sodium molybdate reagent, mix.
8. Add .4 ml stannous chloride diluted reagent, mix immediately, wait 2 min and read 1t 600 nm.
9. Go to your P std curve and look for the OD of each preparation, read off the concentration of P in ug/ml and then make a plot of P conc versus time elapsed in min. It should be a straight line, with the slope of the line being the enzyme activity in ug/ml/min. Usually enzyme activity is expressed as ug p/mg protein/min. Our activity is the slope of our line, divided by the final concentration in mg/ml after diluting it 1/10 by adding 2.5 ml to 25 ml reaction mix.
The effects of actin, calcium, ionic strength, pH, magnesium, and temperature can be studied on myosin ATPase. You can try assays without each of the above chemicals , or with half the amount, and the physical parameters can also be changed (room temp, pH 8 OR 5). Ionic strength can be changed by adding more or less NaCl. KCl causes precipitation of the Pi reagents, so don't use it. I want you to try the regular assay above and the effect of at least one of these bottom alterations. Do something different from the other groups around you so that you can all compare results. The slope of your plot for the assay under different conditions should be different. Put them all on the same graph but label them clearly. You should observe the reaction mix after you add your myosin (between the mad rush to pipette) to see if the myosin is soluble (clear solution) or precipitating (cloudy). See if it seems to work best or worst when just starting to ppt. However, this means you must stir it before you pipette, so you don't draw off all the myosin in the first sample for the blank, or any subsequent sample.
Lowry protein determinations: try three samples: (remember always do duplicates and don't forget the water blank) full strength, 1/5, 1/10 on each preparation. That means you will use .5 cc prep full strength, .1 cc prep+.4cc water, and 0.05cc prep+ .45cc water. (Use a water blank). Record your results on the answer sheet using your standard curve from before to read the amount of protein present. Make sure you take into account the dilutions. How do your duplicates compare? How do your different dilutions compare in the answer they give you for the original protein content? If you don't get good results, do it over.
ACTIN POLYMERIZATION (see separate writeup in this manual) two of you can do the actin polymerization experiment, since it becomes more difficult to polymerize as it ages. Use the viscometry setup. Use your actin full strength. Do not dilute. When salt is added to give a concentration of 0.2 M KCl, F actin forms by polymerization.
TRY TO SEPARATE
PHOSPHORYLATED PROTEINS FROM NON
REF:DULCLOS, B.,
MARCANDIER, S., COZZONE, AJ. CHEMICAL PROPERTIES AND SEPARATION OF PHOSPHOAMININO
ACIDS BY THIN-LAYER CHROMATOGRAPHY AND/OR ELECTROPHORESIS. Meth. Enzymol:201:
10-21.1991
Vacquier, V. and GW
Moy Microchemical determination of phosphate in proteins isolated from
polyacrylamide gels. same vol p 261-264.
O-phosphates on serine-threonine,
tyrosine
N-phosphates
arginine-histidine, lysine
acyl-phos aspartic
and glutamic
Acid precipitation
usually used and this destroys last two types, so only o-type can be done.
WHAT TO DO WITH THE
SUPERNATE FROM CENTRIFUGATION to separate membranes.
From Vacquier- make
homog 10% in TCA with powder w/v in cold, spin 10,000g 10min, wash in 90% v/v
acetone, spin 3000g 10min. can dissolve in 10% w/v SDS for electrophoresis, but
for ours
USE THE meth in 1st
ref: hydrolysis of protein for 2 hr in 6N HCl at 110 degrees (shorter time get
more P-Tyr, longer more PThr)
Get TLC plastic
sheet cellulose plates 0.1 mm thickness, 20x20 cm Merck without fluorescent
indicator. Spot
ascending chromatog
in solvent A 10-12 hr or B 7-9 hr. Stain with ninhydrin prepared by mix 1 vol
0.33% ninhydrin in tert-butanol with 1 vol acetic acid-pyridine-water (1:5:5,
v,v,v).
Do 2d- solvent a
first, then b in second dimension
solvent a:5vol
isobutyric acid-3vol 0.5M NH4OH
solvent B :7vol
2-propanol-1.5volHCL-1.5 vol H2O
Prepare
fertilized eggs as in the fertilization exercise. Resuspend .1 ml eggs
into ten ml of the following drugs in seawater and pour into a petri
dish; all at 10 uG/ML
1. D
actinomycin
2.
PUROMYCIN
3.
COLCHICINE
4.
VINBLASTINE
5.
CYTOCHALASIN
6.
DEXAMETHASONE
7. DNP
8.
ARSENIC
9.
CYANIDE
10. Place
.1 ml eggs into normal seawater as a control.
11. Place
a similar control on ice.
12. Place
a control at 37 degrees.
Observe to see
when cleavage occurs, or if it occurs. Determine whether each drug or
treatment should work at the nuclear level or spindle level, or cleavage furrow
level, or metabolic level.
ISOLATION OF
MITOTIC APPARATUS
Remove
the vitelline membrane from unfertilized eggs by treatment in 3 mM
dithiothreitol (DTT), pH 9 for ten minutes. Decant off the supernatant from the
settled eggs (they will settle during the ten minutes.) Wash 2x with sea water
and then fertilize as in fertilization exercise. You will not be able to see a
membrane elevate, since it is gone, so it would be a good idea to reserve a few
eggs that are not treated with dtt to fertilize at the same time, to be sure
the sperm is good. After fertilized eggs settle, resuspend them in Cam
nitex cloth, place in an ice bath, and observe to see that cells are
broken. Spin at 200 g to sediment mitotic apparatus (at 0 degrees
for 30 min.) Add CaCl2 to a concentration of .1 mM to halve the
mitotic apparatus. Observe and freeze
ISOLATION
MEDIUM 1 M SUCROSE, .15 M DITHIODIGLYCOL, 1 mM EDTA pH6.4. An
alternative is 20 mM MES, 10 mM EGTA, 1 mM MgCl2 pH 6.4.
REFERENCES:
Mazia et al. The direct isolation of the mitotic apparatus. J. Biophys biochem
cytol. 10: 467
References: Cell
15:935
Stock
solutions: 1. DNAase I
Equipment:
quartz cuvettes, micropipettes
Purpose:
to make a standard curve of inhibition of DNAase by G
Step 1.
detection of DNAase without inhibition. This is done by mixing 10ul of DNAase
with 3 ml DNA (solutions above) and immediately observing OD at 260 nm over a
period of 5 min. We will have to use the spectrophotometer in the adjacent
room. It holds four cuvettes, so several can be done at once from the different
groups by reading in series. Plot the results and get a slope.
Step 2.
detection of g
1. 20 ug/ml
2. 100 ug/ml
3. 300 ug/ml
4. 400 ug/ml
5. 600 ug/ml (if your actin is not this concentrated, make a similar but more
dilute series.)
Now place 15
Step 3. Now
prepare some Ft quanidine from the value in the test with guanidine, and that
is the amount of F
VISCOSITY MEASUREMENTS OF ACTIN
POLYMERIZATION TO F ACTIN From the protein readings you took on the actin, figure out the mg/ml.
If it is cloudy or has particles in it, it must be centrifuged or it will clog the viscometer..
If you have 5 mg/ml, for the experiments below, you would take 5 ml and add tris KCl and ATP to the actin in the bulb of the viscometer, ROTATE to mix, RECORD THE TIME, and do a viscosity measurement by reading the number of seconds for the actin to traverse the distance between the two cross marks and record it. Do that every 2 minutes or however long it takes to run the volume through in case that is more than two minutes. Stir the actin in the bulb between readings by rotating the viscometer. Keep the readings going for 15 minutes. Now try to see if actin will polymerize in the presence of an oxidizing agent. CHECK TEMPERATURE WHEN YOU START TO MEASURE THEIR VISCOSITY.
ACTOMYOSIN VISCOSITY Prepare the actomyosin by adding some unfrozen myosin (1/5 the concentration of the actin) to a diluted 5 ml preparation. Try to have a concentration which will give an initial flow time at room temperature of 2e? (Remember in trying to explain the results that there is
Unfertilized or
fertilized eggs prepared according to the fertilization exercise are washed
after settling in 5 volumes of 0.1 M MgCl2, 1 mM Tris pH 8 to stabilize the cell
membranes and cortex. They are centrifuged at 5000 rpm for 5 min, and
homogenized in 10 mM MgCl2
OBTAIN EGGS,
FERTILIZE THEM, AND PREPARE CORTICAL HULLS AS IN OTHER EXPERIMENTS.
ASSAY THE ATPASE
WITH THE FOLLOWING REACTION MIXTURE:
MOLARITY
VOLUME FINAL CONC
MgCl2
0.6M .05
mL
NaCl
1.5M
.9 150mM
KCl
1.5
.2
33 mM
ATP
.02
1.3
2.88 mM
TRIS
1 M
1.8mL 200 mM
PROTEIN
1.2 mL amount TO BE DETERMINED
BY BIORAD
USING MATERIAL LEFTOVER
WATER
3.55
mL
TOTAL
9.0 mL
THIS GIVES
YOU ENOUGH FOR FOUR 2 ML SAMPLES, A ZERO AND THREE OTHERS.
TAKE OUT SAMPLES
AS FOR MYOSIN ATPASE AND DETERMINE THE Pi CONTENT AS FOR MYOSIN ATPASE. THIS
ENZYME IS LESS ACTIVE, SO USE LONG TIME PERIODS LIKE 5,10,15 MINUTES AT 35
DEGREES.
SUBSTITUTE NITROPHENYLPHOSPHATE IN THE REACTION AND READ ON THE
SPECTROPHOTOMETER DIRECTLY, WITHOUT THE ADDITION OF THE Pi DETECTION REAGENTS.
VARY THE ASSAY BY LEAVING OUT BOTH Na+ AND K+ TO SEE THE LEVEL OF Mg++
ATPASE. TO MAKE SURE IT IS NOT A Ca++ ATPASE, SUBSTITUTE Ca++ FOR Mg++ IN
ONE EXPERIMENT, OR ADD EGTA TO THE SAME MOLARITY AS THE Mg++.