Timeline of sexual development (masculine)

From Mad Gender Science!

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Fetal Development

Main article: SRY signaling cascade

  1. The SRY gene on the Y chromosome acts binds to the TESCO promoter sequence on DNA, causing SOX9 to be produced, but shuts down 3 days later.
  2. SOX9 continues to promote at TESCO, which leads the transcription of more SOX9 and a protein called DMRT1.
  3. DMRT1 also upgregulates at TESCO, but in addition blocks the transcription of FOXL2, which is part of the female gene regulatory network.
  4. Gonadal cells differentiate into Leydig and Sertoli cells due to the action of SOX9. Additional hormones such as Anti-Mũllerian Hormone, Testosterone/DHT etc. are released, and the tissue organizes into the male testis.

Puberty Induction

Main article: Hypothalamic-pituitary-gonadal axis

  1. The HPG axis becomes active at the start of puberty when a cluster of GnRH-producing neurons finishes its slow migration to the hypothalamus.
  2. GnRH pulses released by these neurons stimulates the production of FSH and LH (gonadotropins) in the pituitary gland.
  3. FSH and LH stimulate the production of testosterone in the testes.
  4. Testosterone inhibits the production of FSH and LH in the pituitary gland, to prevent too much circulating testosterone.
  5. Masculinization occurs as testosterone binds to the androgen receptor in many different tissues.

Masculinization from the Androgen Receptor

  • Vocal fold tissue lengthens, and the larynx protrudes to cause an "adam's apple".
  • Sebum production increases in skin cells, causing acne.
  • Bone Morphogenic Protein is activated in osteoblasts, causing skeletal structure to masculinize.
  • Androgenic body hair goes from vellum hair to pigmented, thicker terminal hair as the hHa7 keratin gene is activated (facial hair growth).
  • Growth Hormone and IGF-1 are stimulated, causing the Epiphyseal plate to form later than in feminine development.
  • Enlargement of penis and scrotal sack.
  • Many other things

See also