Lefebvre Final

Question 1

Factors needed to maintain TSCs in vitro

Answer 1

FGF4 + TGFB1/activin

Question 2

Where/when to derive TSCs

Answer 2

1. polar TE (E3.5)
2. EXE (5.5-6.5)
3. chorionic ectoderm (E7.5-8.5)

Question 3

How to differentiate TSCs in vitro

Answer 3

Remove FGF4 or add differentiation factors

Question 4

3 trophoblast lineages in humans

Answer 4

1. cytotrophoblast
2. syncytiotrophoblast
3. extravillous trophoblast

Question 5

Three types of placentas and the animals they are found in

Answer 5

1. epitheliochorial (cow, pig, horse)
2. endotheliochorial (dog, cat)
3. hemochorial (mouse, human)

Question 6

Functions of giant cells in the mouse placenta

Answer 6

nutrient transport, remodelling of maternal uterine blood vessels, production of placental hormones

Question 7

How are giant cells formed in the mouse placenta?

Answer 7

endoreplication –> S phase w/o cytokinesis/mitosis –> makes large nucleus/cells that are polyploid

Question 8

How are syncytium cells formed?

Answer 8

fusion of several diploid nuclei

Question 9

Three layers of mature placenta

Answer 9

1. TGCs
2. Spongiotrophoblast layer (junctional zone) = SpT + GlyT
3. Labyrinth layer

Question 10

How can fetal and maternal RBCs be distinguished?

Answer 10

Fetal RBCs have a nucleus, whereas maternal RBCs are anuclear

Question 11

Hemochorial

Answer 11

Maternal blood directly bathes fetal trophoblast

Question 12

Hemotrichorial

Answer 12

Three layers separate maternal and fetal blood: 2 x SynT + 1 x TGCs

Question 13

Function of SpA-TGCs (spiral artery-associated TGCs)

Answer 13

Invade the decidua and remodel maternal vasculature

Question 14

Function of C-TGCs (maternal blood canal TGCs)

Answer 14

Line the central canal at the spongiotrophoblast layer

Question 15

Function of sTGCs (sinusoidal TGCs)

Answer 15

Line the blood spaces (sinuses) which the fetal blood vessels bathe in

Question 16

Proteins expressed by PGCs

Answer 16

Blimp1
Fragilis
Stella
Oct4

Question 17

Factor secreted by EXE that induces PGCs

Answer 17

BMP4

Question 18

Where/when are precursor PGCs found?

Answer 18

Proximal epiblast, posterially near PS

E6.25

Question 19

Position of PGCs at E7.5

Answer 19

At base of allantois (specified PGCs)

Question 20

Position of PGCs at E8.5

Answer 20

Hindgut endoderm

Question 21

Position of PGCs at E9.5

Answer 21

Gut endoderm

Question 22

Position of PGCs at E10.5

Answer 22

Genital ridges

Question 23

Migratory path of PGCs

Answer 23

Proximal epiblast
Base of allantois 
Hindgut endoderm 
Gut endoderm 
Genital ridges

Question 24

Factor that guides PGC migration and where it is secreted

Answer 24

SDF1/CXCL12 - secreted by dorsal wall
Binds CXCR4 (SDF1 receptor on PGCs) and guides migration to genital ridges

Question 25

Gene required for apoptosis of ectopic PGCs

Answer 25

Bax

Question 26

Factors required for ESCs or iPSCs to be converted to EpiLCs

Answer 26

Activin A, FGF4

Question 27

Factors required for EpiLCs to be converted to PGCLCs

Answer 27

BMP4, LIF, SCF, EGF