Lefebvre Final Flashcards
Factors needed to maintain TSCs in vitro
FGF4 + TGFB1/activin
Where/when to derive TSCs
- polar TE (E3.5)
- EXE (5.5-6.5)
- chorionic ectoderm (E7.5-8.5)
How to differentiate TSCs in vitro
Remove FGF4 or add differentiation factors
3 trophoblast lineages in humans
- cytotrophoblast
- syncytiotrophoblast
- extravillous trophoblast
Three types of placentas and the animals they are found in
- epitheliochorial (cow, pig, horse)
- endotheliochorial (dog, cat)
- hemochorial (mouse, human)
Functions of giant cells in the mouse placenta
nutrient transport, remodelling of maternal uterine blood vessels, production of placental hormones
How are giant cells formed in the mouse placenta?
endoreplication –> S phase w/o cytokinesis/mitosis –> makes large nucleus/cells that are polyploid
How are syncytium cells formed?
fusion of several diploid nuclei
Three layers of mature placenta
- TGCs
- Spongiotrophoblast layer (junctional zone) = SpT + GlyT
- Labyrinth layer
How can fetal and maternal RBCs be distinguished?
Fetal RBCs have a nucleus, whereas maternal RBCs are anuclear
Hemochorial
Maternal blood directly bathes fetal trophoblast
Hemotrichorial
Three layers separate maternal and fetal blood: 2 x SynT + 1 x TGCs
Function of SpA-TGCs (spiral artery-associated TGCs)
Invade the decidua and remodel maternal vasculature
Function of C-TGCs (maternal blood canal TGCs)
Line the central canal at the spongiotrophoblast layer
Function of sTGCs (sinusoidal TGCs)
Line the blood spaces (sinuses) which the fetal blood vessels bathe in
Proteins expressed by PGCs
Blimp1
Fragilis
Stella
Oct4
Factor secreted by EXE that induces PGCs
BMP4
Where/when are precursor PGCs found?
Proximal epiblast, posterially near PS
E6.25
Position of PGCs at E7.5
At base of allantois (specified PGCs)
Position of PGCs at E8.5
Hindgut endoderm
Position of PGCs at E9.5
Gut endoderm
Position of PGCs at E10.5
Genital ridges
Migratory path of PGCs
Proximal epiblast Base of allantois Hindgut endoderm Gut endoderm Genital ridges
Factor that guides PGC migration and where it is secreted
SDF1/CXCL12 - secreted by dorsal wall Binds CXCR4 (SDF1 receptor on PGCs) and guides migration to genital ridges
Gene required for apoptosis of ectopic PGCs
Bax
Factors required for ESCs or iPSCs to be converted to EpiLCs
Activin A, FGF4
Factors required for EpiLCs to be converted to PGCLCs
BMP4, LIF, SCF, EGF
