Question

Explain spermatocytes

Answer 1

Spermatocytes:
Spermatocytes are germ cells in the testes of animals that are engaged in meiosis. The testes contains populations of cells, named spermatogonia, that proliferate by mitotic division to yield new cells. As is usually the case for mitotic division, these cells are equivalent with respect to the DNA content of their nuclei. After one or more mitotic divisions, spermatogonia divide to form spermatocytes.Spermatocytes differ from spermatogonia in that they enter meiosis and engage in the genetic recombination that characterizes this process. They are the only cell type in the male body where meiosis occurs. Genetic recombination shuffles the genome so that new combinations of genetic material are created and the resulting cells have a genetic endowment that differs from the starting spermatogonial cell. After committing to meiosis, two cellular divisions occur where the 4n primary spermatocyte divides to form two 2n secondary spermatocytes (n refers to one complete copy of the genetic material). In turn, each secondary spermatocyte divides to form two 1n spermatids. The genetic recombination associated with meiosis occurs in the primary spermatocyte. In many animals,spermatocytes divide incompletely so that cells remain connected by passageways of cytoplasm. These passageways allow the free exchange of macromolecules, such as proteins and other materials, between connected cells. The significance of these passageways is thatspermatocytes are nearly identical with respect to the proteins they contain even though the DNA template in their nucleus can differ due to genetic recombination that had occurred during meiosis. Although there have been some advances in our understanding in recent years, how a spermatocyte exits mitosis and enters meiosis is still poorly understood. It is also unknown how incomplete cell division associated with cytoplasmic passageways occurs during the formation of spermatocytes