Lets Clone a Mouse Somatic Cell Nuclear Transfer

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 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.