Maris Exam 2

Question 1

What is a stem cell niche?

Answer 1

A microenvironment where stem cells are populated

Question 2

What kind of signals are produced by stem cell niches?

Answer 2

Germline differentiation signals of embryonic stem cells

Question 3

Stem cell must be attached to the _____ to differentiate.

Answer 3

Microenvironment

Question 4

What does the size of the microenvironment effect stem cells?

Answer 4

Large space multiple stem cells can differentiate
Medium sized possibly only one stem cell can differentiate
Small space the stem cells might have to find another location to adhere to and differentiate
Prevents overpopulation

Question 5

What produced GDNF?

Answer 5

Sertoli cell niches

When they leave the niche they differentiate

Question 6

When the germ line of stertoli cells was depleted what does it lead to?

Answer 6

Sterility

Question 7

What does over production for the steroli cell germ line lead to?

Answer 7

Tumor formation

Undifferentiated, non-apoptoic spermatogonia