Transcript Let’s Clone a Mouse

Let’s Clone a Mouse
Somatic Cell Nuclear Transfer
Remember what you learned
yesterday?
Artificial Embryonic Twinning- when a scientist
mimics natural cloning by separating an embryo
and allowing it to briefly develop in a Petri dish
before implanting into a surrogate
Somatic Cell Nuclear Transfer- when the nucleus
of a somatic cell is transferred into an enucleated
egg (egg where nucleus is removed) and is then
placed in a surrogate
Ok, so let’s begin…
On your lab bench you have 4 Petri dishes, 3
mice, 1 mouse pup, and a morula (a solid ball of
cells resulting from division of a fertilized ovum).
You also have questions.
Try to answer these as you go.
Better yet, see how many you can answer now!
It’s a good way to see how much you remember
from yesterday’s class discussion.
Color the cells.
Color the cells as follows:
Cumulus Cell Nucleus and Cumulus Cell = Blue
Egg Cell Nucleus and Egg Cell = Blue
Morula (ball of cells) = Green
Color the mice.
Color the 3 large female mice as follows:
Somatic Cell Donor = Brown
Egg Cell Donor = Black
Surrogate Mother = White
Don’t color the mouse pup yet!
Somatic Cell Donor
From the brown mouse, cut out the Cumulus
Cell and place it in Petri Dish #1.
Remember, this is the mouse you are cloning!
Egg Cell Donor
From the black mouse, cut out the Egg Cell
and place it in Petri Dish #2.
THINK: Do you need this mouse’s DNA?
Enucleate the Egg Cell
Cut out and discard the nucleus from the Egg Cell
in Petri Dish #2. Move the enucleated Egg Cell to
Petri Dish #3.
THINK: At this point, is there any DNA in the egg?
Cumulus Cell
Cut out the nucleus from the Cumulus Cell in
Petri Dish #1.
Transferring…
Transfer the Cumulus Cell Nucleus into the
Enucleated Egg Cell in Petri Dish #3 by taping them
together on the back.
THINK: An adult mouse has 40 chromosomes. How
many chromosomes does the egg cell have right
now?
Waiting time!
Transfer the Egg Cell with the newly replaced
nucleus onto Petri Dish #4 and let it rest for a
minute. This waiting time represents the 1-6
HOURS that the new nucleus needs to adjust to
the Egg Cell.
Now it’s a morula!
After it is chemically stimulated, the new Egg
Cell divides into a ball of cells called a Morula.
Cover the new Egg Cell with the Morula.
Surrogate
After the Egg Cell divides into a Morula, it is
placed into the womb of the Surrogate Mother.
After about 19 days, the Surrogate Mother will
give birth to a new Mouse Pup.
THINK: Which adult mouse will the mouse
pup resemble? What color will it be?
Color the newly delivered Mouse Pup this
color.
Tidy your lab station- throw away
your trash paper bits and place
mouse and keyboard up.
Finish answering questions.