Overview Introduction A process by which spermatogonia develop into spermatozoa begins at puberty requires 64 days (approximately 2 months) Broken down into spermatogenesis the formation of spermatids from spermatogenic cells spermiogenesis the process of spermatids maturing into mature sperm Spermatogenesis Spermatogenic cells are organized in poorly defined layers of progressive development between adjacent Sertoli cells in seminiferous tubules Spermatogonia (2N), most immature spermatogenic cells, rest on basal lamina spermatogonia occupy basal compartment in seminiferous tubules Spermatogonia (2N) divide by mitosis produces primary spermatocytes (2N) Primary spermatocytes (2N) replicate DNA (4N) primary spermatocytes move across Sertoli cell - Sertoli cell junctional complexes into luminal compartment in seminiferous tubules Primary spermatocytes (4N) divide by meiosis I produces 2 haploid secondary spermatocytes (2N) nondisjunction at this stage can lead to Klinefelter syndrome Secondary spermatocytes (2N) divide by meiosis II produces 4 haploid spermatids (1N) Spermiogenesis Spermatids (1N) differentiate into spermatozoa (1N) by an extensive remodeling process Loss of cytoplasm, gain of acrosomal cap, and flagellum (tail) acrosomal cap develops via Golgi apparatus flagellum (tail) develops via centrioles Spermatozoa Head acrosomal cap and nucleus Tail neck middle piece mitochondria provide energy for movement of flagellum (tail) sperm motility principal piece end piece Nutrition spermatozoa feed on fructose