The Collaborative International Dictionary
Spermatogonium \Sper`ma*to*go"ni*um\, n. [NL., fr. Gr. ????, ???, sperm + ??? offspring.] (Physiol.) A primitive seminal cell, occuring in masses in the seminal tubules. It divides into a mass (spermosphere) of small cells (spermoblast), which in turn give rise to spermatozoids.
Wiktionary
n. (context biology English) Any of the undifferentiated cells in the male gonads that become spermatocytes; a spermatoblast
Wikipedia
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.
Usage examples of "spermatogonium".
When a spermatogonium was observed to change to a primary spermatocyte-still diploid-it would be segregated and at the instant it divided into two secondary spermatocytes-haploids, one with an X chromosome and one with a Y chromosome-they would be again segregated and each would be encouraged to develop into spermatozoa.
When a spermatogonium was observed to change to a primary spermatocyte—.