Stem Cells II Flashcards
Where are pluripotent stem cells derived from?
Embryos
What are teratomas?
Germ cell tumors
What are the three types of embryo-derived pluripotent stem cells?
ESCs, EGCs, ECCs
Where were embryonal carcinomas first discovered?
Mouse strain 129Sv
PGCs are embryonic (ectoderm/endoderm)
Ectoderm
True or false: ECCs can enter the germ line
False
Where are ESCs derived from?
Inner cell mass of blastocysts
ESCs (can/cannot) be maintained indefinitely in culture
Can
Do ESCs integrate in the normal development process when injected into blastocyst?
Yes
True or false: ESCs can produce placental cells
False
ESCs are (pluripotent/totipotent)
Pluripotent
What are the similarities of ESCs and ICM?
Regeneration activity
Embryos are generated solely from ESCs through _____________ chimerism
Tetraploid
True or false: ESCs can enter the germ line
True
When do ESCs form teratomas?
When transplanted into immunocompatible adults
Where are embryonic germ cells derived from?
PGCs
True or false: EGCs can enter the germ line
True
EGCs are (totipotent/pluripotent)
Pluripotent
Embryo-derived stem cells are (natural/artificial) stem cells that do not exist in the body
Artificial
Which embryo-derived stem cells are used for transgenesis?
ESCs
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
b, d, a, c, e
What are the three genotypes seen from transgenesis?
Wildtype, homozygous and heterozygous
What extrinsic cues maintain mouse ESC self-renewal in vitro?
Feeder cells that secrete LIF and serum that contains BMP4
What is the mechanism of LIF for the maintenance of ESC self-renewal?
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
What is the consequence of withdrawal of LIF and shut-down of STAT3 action?
Differentiation to endoderm/mesoderm
How does LIF maintain ESC pluripotency?
JAK/STAT3 pathway
What is the mechanism of BMP4 pathway?
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
What is the action of removing BMP4 from ESC culture in the absence of LIF?
Differentiation to endoderm/mesoderm
What is the action of removing BMP4 from ESC culture in the presence of LIF?
Differentiation to neural fate
What is the results of removing Smad signaling?
Induction of neuroectodermal differentiation
