Meiosis

Abstract

Meiosis is a feature of sexual reproduction that results in the independent assortment of genetic material from two individuals, providing greater genetic diversity. The initiation of meiosis requires both intrinsic and extrinsic signals. Meiosis is characterized by one round of DNA replication followed by two rounds of cell division, resulting in haploid germ cells. Crossing-over of DNA results in genetic exchange of genes between maternal and paternal DNA. Meiosis occurs in plants and animals and, although the details may differ among species and even between sexes in the same species (e.g., in humans, the timing of meiosis differs between males and females), overall the process is highly conserved.

Keywords

Chromosomes
Crossing-over
DNA replication
Gametes
Haploid cells
Independent assortment
Oocyte
Sexual reproduction
Spermatogonia
Transcription

Michael D. Griswold received his PhD in biochemistry in 1969 and is currently Regents Professor of molecular biosciences at Washington State University. His research area is the study of spermatogenesis with emphasis on the role of Sertoli cells. More recently, he has examined the role of retinoic acid in the initiation of meiosis in the testis of the postnatal male.

Patricia A. Hunt received her PhD in reproductive biology in 1983 and is currently a Meyer distinguished professor in the School of Molecular Biosciences at Washington State University. Her research focuses on mammalian meiosis and the human maternal age effect.

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This article is a revision of the previous edition article by PB Moens, volume 3, pp 1163–1165, © 2001, Elsevier Inc.

Copyright © 2013 Elsevier Inc. All rights reserved.