Stem Cells II

Question 1

Where are pluripotent stem cells derived from?

Answer 1

Embryos

Question 2

What are teratomas?

Answer 2

Germ cell tumors

Question 3

What are the three types of embryo-derived pluripotent stem cells?

Answer 3

ESCs, EGCs, ECCs

Question 4

Where were embryonal carcinomas first discovered?

Answer 4

Mouse strain 129Sv

Question 5

PGCs are embryonic (ectoderm/endoderm)

Answer 5

Ectoderm

Question 6

True or false: ECCs can enter the germ line

Answer 6

False

Question 7

Where are ESCs derived from?

Answer 7

Inner cell mass of blastocysts

Question 8

ESCs (can/cannot) be maintained indefinitely in culture

Answer 8

Can

Question 9

Do ESCs integrate in the normal development process when injected into blastocyst?

Answer 9

Yes

Question 10

True or false: ESCs can produce placental cells

Answer 10

False

Question 11

ESCs are (pluripotent/totipotent)

Answer 11

Pluripotent

Question 12

What are the similarities of ESCs and ICM?

Answer 12

Regeneration activity

Question 13

Embryos are generated solely from ESCs through _____________ chimerism

Answer 13

Tetraploid

Question 14

True or false: ESCs can enter the germ line

Answer 14

True

Question 15

When do ESCs form teratomas?

Answer 15

When transplanted into immunocompatible adults

Question 16

Where are embryonic germ cells derived from?

Answer 16

PGCs

Question 17

True or false: EGCs can enter the germ line

Answer 17

True

Question 18

EGCs are (totipotent/pluripotent)

Answer 18

Pluripotent

Question 19

Embryo-derived stem cells are (natural/artificial) stem cells that do not exist in the body

Answer 19

Artificial

Question 20

Which embryo-derived stem cells are used for transgenesis?

Answer 20

ESCs

Question 21

Place the events of gene targeting for transgenesis in order
a. Injection into blastocysts
b. Homologous recombination in ESCs
c. Transplantation to pseudopregnant females
d. Selection of ESCs modified properly
e. Chimeric offspring

Answer 21

b, d, a, c, e

Question 22

What are the three genotypes seen from transgenesis?

Answer 22

Wildtype, homozygous and heterozygous

Question 23

What extrinsic cues maintain mouse ESC self-renewal in vitro?

Answer 23

Feeder cells that secrete LIF and serum that contains BMP4

Question 24

What is the mechanism of LIF for the maintenance of ESC self-renewal?

Answer 24

LIF binds to receptor and recruits gp130
gp130 has a domain that activates Jak
Jak phosphorylates STAT3
STAT3 dimerizes, enters the nucleus and controls target gene transcription for self-renewal

Question 25

What is the consequence of withdrawal of LIF and shut-down of STAT3 action?

Answer 25

Differentiation to endoderm/mesoderm

Question 26

How does LIF maintain ESC pluripotency?

Answer 26

JAK/STAT3 pathway

Question 27

What is the mechanism of BMP4 pathway?

Answer 27

BMP4 binds to type II receptor and joins type II to type I receptor SMADS is phosphorylated and binds to SMAD4 Activates gene transcription of target genes

Question 28

What is the action of removing BMP4 from ESC culture in the absence of LIF?

Answer 28

Differentiation to endoderm/mesoderm

Question 29

What is the action of removing BMP4 from ESC culture in the presence of LIF?

Answer 29

Differentiation to neural fate

Question 30

What is the results of removing Smad signaling?

Answer 30

Induction of neuroectodermal differentiation