During the process of spermatogenesis, which takes place in the testes, male gametes called sperm are formed.
The formation of gametes, cells responsible for reproduction, is a process generically called gametogenesis. When the process occurs for the formation of the male gamete, we can call it spermatogenesis.
What are the 3 Stages of Spermatogenesis?
Spermatogenesis, the process of sperm formation, occurs in three main stages: the multiplication period, the growth period, and the maturation period.
Period of multiplication:
The precursor cells called spermatogonia (2n) multiply by mitosis. The multiplication, which takes place in the wall of the seminiferous tubules, is relatively slow until puberty, after which it becomes intense. This phase of spermatogenesis can occur throughout a man’s life.
Spermatogonia increase in size and is called primary spermatocytes or I (2n) spermatocytes.
In the maturation period, the process of meiosis takes place. First, primary spermatocytes undergo the first meiotic division and give rise to two secondary spermatocytes or spermatocytes II (n). Then begins the second meiotic division, which gives rise to two spermatids (n).
After the end of the cell division process, the spermatids begin a process called spermiogenesis, in which the transformation of these cells into spermatozoa occurs. In this important step, the spermatid elongates, its nucleus migrates to the most extreme region of the cell, and the acrosome and tail are formed. The acrosome plays a key role in fertilization since it releases substances necessary for penetration into the secondary oocyte. The tail, in turn, is essential for the locomotion of this gamete.