Year: 2019
Type: article
Abstract: Faithful segregation of mammalian X and Y chromosomes in male meiosis depends on pairing and recombination in a short interval of residual sequence homology known as the pseudoautosomal region (PAR)... Faithful segregation of homologous chromosomes at meiosis requires pairing and recombination. In taxa with dimorphic sex chromosomes, pairing between them in the heterogametic sex is limited to a narrow interval of residual sequence homology known as the pseudoautosomal region (PAR). Failure to form the obligate crossover in the PAR is associated with male infertility in house mice (Mus musculus) and humans. Yet despite this apparent functional constraint, the boundary and organization of the PAR is highly variable in mammals, and even between subspecies of mice. Here, we estimate the genetic map in a previously documented expansion of the PAR in the M. musculus castaneus subspecies and show that the local recombination rate is 100-fold higher than the autosomal background. We identify an independent shift in the PAR boundary in the M. musculus musculus subspecies and show that it involves a complex rearrangement, but still recombines in heterozygous males. Finally, we demonstrate pervasive copy-number variation at the PAR boundary in wild populations of M. m. domesticus, M. m. musculus, and M. m. castaneus. Our results suggest that the intensity of recombination activity in the PAR, coupled with relatively weak constraints on its sequence, permit the generation and maintenance of unusual levels of polymorphism in the population of unknown functional significance.
Source: Genetics
Authors: Andrew P Morgan, Timothy A Bell, James J Crowley, Fernando Pardo-Manuel de Villena
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: bronze
Awards: An Interdisciplinary program for systems genomics of complex behaviors, An Interdisciplinary program for systems genomics of complex behaviors, Systems Genetics of Fluoxetine-Induced Neurogenesis and Antidepressant Response, Effects of advanced paternal age on germline genome stability, Collaborative Cross: A system genetics approach to the study of male infertility, Effect of paternal age on mutational burden and behavior in mice, A Carolina Center to Characterize and Maintain Mutant Mice
OpenAlex ID: W2915306247