meiosis

WP

Definition: Meiosis is a specialized type of cell division leading to the production of gametes.

During meiotic prophase I, homologous chromosomes interact with each other and form bivalents (pairs of homologous chromosomes).

Three major meiotic processes — chromosome pairing, synapsis and recombination — are involved in the formation of bivalents.

Chromosome pairing is largely dependent on the initiation and progression of recombination in fungi, mammals and plants, but not in Caenorhabditis elegans or Drosophila. Synapsis and recombination are also tightly linked.

Meiosis is an essential stage in gamete formation in all sexually reproducing organisms.

Studies of mutations in model organisms and of human haplotype patterns are leading to a clearer understanding of how meiosis has adapted from yeast to humans, the genes that control the dynamics of chromosomes during meiosis, and how meiosis is tied to gametic success.

Genetic disruptions and meiotic errors have important roles in infertility and the aetiology of developmental defects, especially aneuploidy.

An understanding of the regulation of meiosis, coupled with advances in genomics, may ultimately allow us to diagnose the causes of meiosis-based infertilities, more wisely apply assisted reproductive technologies, and derive functional germ cells.

References

 Genetics of mammalian meiosis: regulation, dynamics and impact on fertility. Handel MA, Schimenti JC. Nat Rev Genet. 2010 Feb;11(2):124-36. PMID: 20051984

 Pawlowski WP, Cande WZ. Coordinating the events of the meiotic prophase. Trends Cell Biol. 2005 Dec;15(12):674-81. PMID: 16257210

 Gerton JL, Hawley RS. Homologous chromosome interactions in meiosis: diversity amidst conservation. Nat Rev Genet. 2005 Jun;6(6):477-87. PMID: 15931171

 Gudmundsdottir K, Ashworth A. BRCA2 in meiosis: turning over a new leaf. Trends Cell Biol. 2004 Aug;14(8):401-4. PMID: 15308204