At approximately day 1

Testis weight is approximately 850 mg.

Reference [PubMed Link]

Rabinovici J, Jaffe RB. 1990. Development and regulation of growth and differentiated function in human and subhumand primate fetal gonads. Endocrine Reviews 11(4):532-557.

At approximately day 1

Sertoli cells continue to proliferate after birth, until about 1 year of life, then proliferate again before puberty. Sertoli cells also attain adult morphology around the onset of puberty, and stop proliferating at this time.

Duration: 2 weeks

Reference [PubMed Link]

Sharpe RM, McKinnell C, Kivlin C, Fisher JS. 2003. Proliferation and functional maturation of Sertoli cells, and their relevance to disorders of testis function in adulthood. Reproduction 125(6):769-784.