How gender develops This complex process is prone to error: gene mutations or a maldistribution of chromosomes can impair sexual development. By Valentin Amrhein
3rd to 7th week of pregnancy ...................................
Embryonic gonads
Genes: WNT4, RSPO1, FOXL2
Genes: SRY, SOX9, SF1, CBX2
Purely genetic sexual difference
7th to 24th week of pregnancy
.....................................................................................
Ovaries
Testes
GONADS
No hormones necessary from the ovaries
Hormones from the testes (androgens) necessary Anti-Mullerian hormone suppresses development of internal female sex organs
Genes: WNT4, HOXAs
Testosterone
Uterus, vagina
INTERNAL SEX ORGANS
Prostate, sperm ducts
Vulva
EXTERNAL SEX ORGANS
Penis, scrotum
Birth Puberty
Oestrogens
Breasts,…
14
Androgens
SECONDARY SEXUAL CHARACTERISTICS
Swiss National Science Foundation – Swiss Academies: Horizons No. 107
Facial hair,…