Germ Cell Development

Question 1

What are the specification and commitment steps in germ cell development?

Answer 1

Specification: blimp1 expression
Commitment: Stella

Question 2

When do specification and commitment occur?

Answer 2

5.5-6.5 days

Question 3

How do germ cells actively migrate to the gonads?

Answer 3

Move through the midline and the out to the gonads.

Question 4

What are the four steps of germ cell development?

Answer 4

Specification, commitment, migration, colonisation.

Question 5

When does extensive proliferation of germ cells occur?

Answer 5

During migration.

Question 6

What two hormones drive the development of the male reproductive system?

Answer 6

Anti-Mullerian hormone and DHT

Question 7

What is Swyer syndrome?

Answer 7

XY chromosomes with not SRY gene.

Question 8

What is the phenotype of Swyer syndrome?

Answer 8

Externally female, streak ovaries, not secondary sex characteristic, no germ cells, can support gestation.

Question 9

What does colonisation by the germ cells occur?

Answer 9

Weeks 6-8

Question 10

When do cells begin to migrate in humans?

Answer 10

Week 4

Question 11

When does meiosis stop at prophase I in females?

Answer 11

Week 12

Question 12

What is the cause of carcinoma in situ?

Answer 12

Termination of germ cell differentiation and transformation.

Question 13

What is the potency of seminoma cells?

Answer 13

Pluripotent

Question 14

What is the function of Sertoli cells?

Answer 14

SRY gene
Anti-Mullarian hormone
Regulation of spermatogenesis
Blood-testicular barrier

Question 15

What is the syncytium?

Answer 15

Connections between cytoplasms of germ cells-spermatids to ensure all sperm are identical.

Question 16

What is the function of Leydig cells?

Answer 16

Produce testosterone

Located between the seminiferous tubules.

Question 17

What is the primordial follicle?

Answer 17

Oocyte surrounded by cells of the ovary before birth

Question 18

What is the oocyte like at birth?

Answer 18

Completely enclosed in follicular

Question 19

What cells inhibit meiosis in oocytes?

Answer 19

Granulosa cells

Question 20

When does meiosis first resume?

Answer 20

12 hours before ovulation

Question 21

What happens once the dominant follicle is established?

Answer 21

It produces inhibin to signal to the pituitary to stop producing FSH so that other follicles die.

Question 22

What are atretic follicles?

Answer 22

Those that die

Question 23

What are the supporting cells of oocytes and sperm?

Answer 23

Granulosa and Sertoli.

Question 24

What factors does the oocyte secrete to promote follicular cell growth?

Answer 24

BMP15 and GDF9

Question 25

List the functions of follicular cells.

Answer 25

Secrete factors for meiotic arrest Low-level androgen production Respond to LH Produce aromatase enzyme to convert androgen to oestrogen

Question 26

List the function of Theca cels.

Answer 26

Angiogenic factor for blood supply to follicle LH secretion Oestrogen production