Year: 1990
Type: review
Abstract: Department of Biology, Tufts University, Medford, MA 02155, USA Keywords: spermatogenesis; haploid gene expression; gene regulation; testis Introduction Spermatogenesis offers an experimental system whereby the gene expression of eukaryotic cells with tetraploid, diploid, and haploid chromosome complements can be compared. Starting from a population of stem cells, the diploid spermatogonia follow one of two lineages. One subpopulation of cells initiates a differentiation process ultimately leading to the spermatozoon while a second, presumably distinct, subpopulation of spermatogonia enters a pathway that maintains and repopulates the stem cells of the testis. The cells destined to become spermatozoa undergo several spermatogonial divisions. The last complete replication of DNA during spermatogenesis, in the preleptotene primary spermatocyte, heralds the start of meiosis. During the lengthy interval of meiotic prophase, homologous chromosomes synapse and genetic recombination occurs, producing the genetic diversity required for survival of a species. Following meiotic recombination, the 4N spermatocytes divide twice
Source: Reproduction
Author: N. B. Hecht
Institution: Tufts University
Language: English
Subfield: Reproductive Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W1983951002