Gametogenesis Flashcards
What is a gamete?
Mature haploid germ cell
What is genesis?
Formation
When does gametogenesis occur?
At puberty, from birth, in utero
What chromosomes do the male have?
X and Y
What gene is found on the Y chromosome?
SRY gene
Where is the SRY gene found?
Pre sertoli cells
What does the SRY gene do?
Gives instruction to make sertoli cells
What other gene does SRY switch on?
Sox9
What does the Sox9 do?
Turns on testicular genes
When would it turn into ovaries?
After 11.3 dpc as Sox9 expression is not maintained
What genes are found in the female?
Wnt4 & Foxl2
Where are Wnt4 & Foxl2 found?
Expressed by granulosa cells
How are the female genes suppressed?
By the SRY
What endocrine features control testis development?
Leydig cells: androgens - Sertoli cells: AMH hormone
What does the AMH do?
Develops the seminiferous cords
If theres a lack of AMH what does it mean?
A uterovaginal canal forms from mullerian duct
What do primordial germ cells do?
Go through mitotic proliferation
What are the main 3 stages of it?
Mitotic proliferation, meiotic division, cytodifferentation
What are the first two stage called together?
Spermatocytogenesis
What is the last stage called?
Spermiogenesis
Describe the mitosis stage?
Spermatogonium splits into a type A and type B spermatogonium
Describe the Meiosis 1 stage?
The type B spermatogonium becomes a primary spermatocyte
What is the ending of Meiosis 1 stage?
The primary spermatocyte splits into 2 secondary spermatocytes
What is the meiosis 2 stage?
The 2 secondary spermatocytes break into 4 spermatids
