AskDefine | Define spermatogonium

User Contributed Dictionary

English

Noun

  1. Any of the undifferentiated cells in the male gonads that become spermatocytes; a spermatoblast

Extensive Definition

A spermatogonium (plural: spermatogonia) is an intermediary male gametogonium (a kind of germ cell) in the production of spermatozoa.
There are three subtypes:
  • Type A(d) cells, with dark nuclei. These cells divide to produce copies of themselves, thereby ensuring 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

tubule of the testis of a rat. X 250.

Source

This article includes material from Biology Online.
spermatogonium in German: Spermatogonium
spermatogonium in French: Spermatogonie
spermatogonium in Japanese: 精原細胞
spermatogonium in Portuguese: Espermatogônia
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