Gametogenesis

Question 1

What is gametogenesis?

Answer 1

The process by which gametes (sperm and egg) are formed

Question 2

WHat do germ cells give rise to?

Answer 2

Gametes–> give a genetic contribution to the next generation

Question 3

Three key functions of the germ cells?

Answer 3

Preservation of genetic integrity of the germline
Generation of diversity
Transmission of genetic info to next gen

Question 4

How is gametogenesis compartmentalised in mammals?

Answer 4

Separation of somatic cells and gametes
Enables sex specific differentiation into sperm and egg

Question 5

What is the one process in mammals when meiosis occurs?

Answer 5

Gametogenesis

Question 6

What is pre patterning of gametes?

Answer 6

the establishment of developmental instructions in sperm and egg cells before the onset of the zygote’s own genetic program

Question 7

Why is it difficult to tell if mammalian germ cells are pre patterned?

Answer 7

Mammalian egg cells are v small

Question 8

Where do primordial germ cells migrate to in mammals, and what takes place?

Answer 8

Developing gonads, where meiosis takes place

Question 9

Where is germplasm found?

Answer 9

In oocytes

Question 10

Role of germplasm?

Answer 10

Part of the egg that predetermines germ cells

Question 11

What is Xcat2 a determinant of?

Answer 11

Gametogenesis

Question 12

Why do primordial germ cells (PGCs arise)?

Answer 12

As a result of differentiation in the embryo

Question 13

What are PGCs precursors of?

Answer 13

Gametes (both sexes)

Question 14

How does PGC differentiation come about?

Answer 14

Exogenous cues–> induction

Question 15

Where in an embryo do PGCs arise?

Answer 15

Posterior proximal epiblast

Question 16

Are all cells in the posterior proximal epiblast PGCs?

Answer 16

No, and none of them ate PGCs at he start

Question 17

What is the first step of creating PGCs?

Answer 17

Wnt signals from the visceral endoderm renders proximal epiblast cells sensitive to BMP

Question 18

What effect does BMP produced by extraembryonic ectoderm have on proximal epiblast cells?

Answer 18

Induces Blimp1 and Prdm14

Question 19

What genes do Blimp1 and Prdm14 effect?

Answer 19

Repress somatic gene expression
Activates Stella, Fragilis, Nanos3
Activates pluripotency genes Sox2 and Nanog

Question 20

How do Blimp1 and Prdm14 repress somatic gene expression?

Answer 20

Via Tcfap2c

Question 21

Where are embryonic germ cells derived from?

Answer 21

PGCs

Question 22

Blastocyst structure?

Answer 22

Hollow sphere w/ a single cell layer

Question 23

What is the cell type with the highest differentiation ability?

Answer 23

Pluripotent cells

Question 24

Where do mammalian PGCs migrate to in the embryo?

Answer 24

Hindgut endoderm

Question 25

What happens to the mammalian PGCs during migration to the hindgut endoderm?

Answer 25

They divide

Question 26

Where do the mammalian PGCs go after the hindgut endoderm?

Answer 26

To the hindgut anterior

Question 27

Where do the mammalian PGCs go after the dorsal gut mesentery?

Answer 27

Genital ridges

Question 28

What travels with the PGCs?

Answer 28

Support cells

Question 29

Role of support cells that migrate w/ the PGCs?

Answer 29

maintain undifferentiated stem cell phenotype (travelling niche)

Question 30

What is SDF1 (stromal cell derived factor 1)?

Answer 30

A chemoattractant that has a receptor, CXCR4, on PGCs