L3 - ES cells 2

Question 1

Define pluripotency

Answer 1

The ability to self-renew or differentiate into any cell of the three germ layers

Question 2

What are the three main factors that act to keep a cell pluripotent?

Answer 2

Oct4
Sox2
Nanog

Question 3

What is Oct4?

Answer 3

A POU homeobox trsc factor 
It acts to maintain SC in pp state 
No oct4 = trophectoderm 
Upreg oct4 = mesoderm
Repression loop with cdx2

Question 4

What is Sox2?

Answer 4

High mobility group domain transcription factor
No sox2 = no epiblast
Required in lineage leading to epiblast formation

Question 5

What is nanog?

Answer 5

Essential for self renewal 
It is a transcription factor 
Transient expression in the embryo 
No nanog = visceral and parietal endoderm fornamtion 
increase nanog = no need for LIF/BMP

Question 6

What does the heterogeneity of the SC compartment tell us?

Answer 6

The compartment is dynamic and has the ability to restore other stem cell populations - it is not fixed

Question 7

What are SSEA2 and TRA160?

Answer 7

Cell surface markers. SSEA2 labels very undifferentiated cells where TRA160 labels cells that are almost fully committed to a fate

Question 8

What effect would mutations that affect a SC ability to diff or die have?

Answer 8

It would increase the chance of self renewal. These mutations seem to cluster on particular chromosomes.