Friday 21 November 2003
Crossovers (COs) are essential for meiosis and contribute to genome diversity by promoting the reassociation of alleles, and thus improve the efficiency of selection.
COs are not randomly distributed but are found at specific regions, or CO hotspots. Recent results have revealed the historical recombination rates and the distribution of hotspots across the human genome.
Surprisingly, CO hotspots are highly dynamic, as shown by differences in activity between individuals, populations and closely related species.
DNA methylation could have a role in preventing the formation of COs, a regulation that might explain, in part, the correlation between recombination rates and GC content in mammals. (#17434233#)
Homologous recombination is a dynamic process by which DNA sequences and strands are exchanged. In meiosis, the reciprocal DNA recombination events called crossovers are central to the generation of genetic diversity in gametes and are required for homolog segregation in most organisms.
Cromie GA, Smith GR. Branching out: meiotic recombination and its regulation. Trends Cell Biol. 2007 Sep;17(9):448-55. PMID: #17719784#
Buard J, de Massy B. Playing hide and seek with mammalian meiotic crossover hotspots. Trends Genet. 2007 Jun;23(6):301-9. PMID: #17434233#
Jeffreys AJ, Holloway JK, Kauppi L, May CA, Neumann R, Slingsby MT, Webb AJ. Meiotic recombination hot spots and human DNA diversity. Philos Trans R Soc Lond B Biol Sci. 2004 Jan 29;359(1441):141-52. PMID: #15065666#
Hassold T, Sherman S, Hunt P. Counting cross-overs: characterizing meiotic recombination in mammals. Hum Mol Genet. 2000 Oct;9(16):2409-19. PMID: #11005796#