Stem Cells III

Question 1

MAPK signaling is mediated by which protein?

Answer 1

Erk

Question 2

What is the role of MAPK signaling?

Answer 2

Predisposes mouse ESCs to differentiation commitment

Question 3

When can ESCs be established without LIF and serum?

Answer 3

When Erk is suppressed by a combination of Erk inhibitors

Question 4

MAPK signaling is stimulated by which growth factor?

Answer 4

FGF4

Question 5

LIF and BMP4 (enable/counteract) the action of MAPK signaling that induces differentiation commitment

Answer 5

Counteract

Question 6

What are the intrinsic factors that regulate ESC self-renewal?

Answer 6

Oct4, Nanog, Sox2

Question 7

Oct4-negative embryos differentiate to what in vitro?

Answer 7

Trophectoderm

Question 8

Oct4 (downregulation/upregulation) is the trigger for the formation of the primitive endoderm

Answer 8

Upregulation

Question 9

Nanog over-expression leads to the formation of what cells?

Answer 9

LIF independent ESCs

Question 10

Nanog KO leads to the formation of what type of cells?

Answer 10

Primitive endoderm

Question 11

Altering the gene dosage of which intrinsic factors modifies the pluripotent phenotype of ESCs?

Answer 11

Oct4 and Nanog

Question 12

What are some active genes regulated by Oct4, Nanog and Sox2?

Answer 12

FGF2, STAT3

Question 13

What are some silent genes regulated by Oct4, Nanog and Sox2?

Answer 13

HOXB1, PAX6

Question 14

What are some pros of ESC application in the clinical setting?

Answer 14

Indefinite source of tissue engineering, any cell type can be produced, genetic manipulation, tissue regeneration

Question 15

What are the cons of using ESCs in the clinical setting?

Answer 15

Tumorigenicity, low efficiency of differentiated target cells, immunocompatibility, ethics

Question 16

What is the biological significance of animal cloning?

Answer 16

Differentiated cells retain a complete set of genetic information
Oocyte cytoplasm can reprogram somatic nuclei

Question 17

What experiment was done to see if ESCs can be generated from committed or terminally differentiated cells?

Answer 17

24 different genes selected from genes expressed in both oocytes and ESCs
Those genes were introduced into fibroblasts
One or combination of genes omitted to see what happens

Question 18

What was the results of omitting gene 7?

Answer 18

Production of ESCs

Question 19

Match the role of the Yamanaka factors to Oct4 and Sox2, c-Myc or KIf4
a. Serves as a co-factor for Oct4 and Sox2 and inhibits cell death
b. Restore and maintain pluripotency
c. Disrupts chromatin and allow Oct4 and Sox2 access to the genome

Answer 19

a. KIf4
b. Oct4 and Sox2
c. c-Myc

Question 20

How are ESCs and iPSCs similar?

Answer 20

Long term self-renewal activity

Question 21

Pluripotent fibroblasts contribute to the __________ of a developing fetus

Answer 21

Tissues

Question 22

Why are ESCs and iPSCs not identical?

Answer 22

No live birth of chimeric offspring, global gene expression and DNA methylation patterns

Question 23

Oct4, Nanog and Sox2 (negatively/positively) control the expression of each other

Answer 23

Positively

Question 24

What is the consequence of the forced activation of the network using Oct4, Sox2, c-Myc and KIf4?

Answer 24

Reprogramming of somatic cells to iSCs

Question 25

How are Yamanaka factors turned off and on?

Answer 25

Tetracyclin

Question 26

Why don’t the transgenes need to be integrated into the host cell genome?

Answer 26

The exogenous Yamanaka factors need to be expressed for a short period of time

Question 27

How are Yamanaka factors transferred?

Answer 27

Small molecules, adenoviruses, modified proteins