Spermatogonium

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Spermatogonium
Germinal epithelium testicle.svg
Germinal epithelium of the testicle. 1 basal lamina, 2 spermatogonia, 3 spermatocyte 1st order, 4 spermatocyte 2nd order, 5 spermatid, 6 mature spermatid, 7 Sertoli cell, 8 tight junction (blood testis barrier)
Testicle-histology-boar.jpg
Histological section through testicular parenchyma of a boar. 1 Lumen of Tubulus seminiferus contortus, 2 spermatids, 3 spermatocytes, 4 spermatogonia, 5 Sertoli cell, 6 Myofibroblasts, 7 Leydig cells, 8 capillaries
Identifiers
Gray's p.1243
MeSH A05.360.490.890.900
Anatomical terminology

A spermatogonium (plural: spermatogonia) is an undifferentiated male germ cell, originating in a seminiferous tubule and dividing into two primary spermatocytes (a kind of germ cell) in the production of spermatozoa.

There are three subtypes:

  • Type A(d) cells, with dark nuclei. These cells replicate to ensure a constant supply of spermatogonia to fuel spermatogenesis.
  • Type A(p) cells, with pale nuclei. These cells divide by mitosis to produce Type B cells.
  • Type B cells, which divide to give rise to primary spermatocytes.

Each primary spermatocyte duplicates its DNA and subsequently undergoes meiosis I to produce two haploid secondary spermatocytes. Each of the two secondary spermatocytes further undergo meiosis II to produce two spermatids (haploid). (1 primary spermatocyte => 4 spermatids)

The spermatids then undergo spermiogenesis to produce spermatozoa.

Additional images[edit]

References[edit]