title: The tricky path to recombining X and Y chromosomes in meiosis.
abstract: Sex chromosomes are the Achilles' heel of male meiosis in mammals. Mis-segregation of the X and Y chromosomes leads to sex chromosome aneuploidies, with clinical outcomes such as infertility and Klinefelter syndrome. Successful meiotic divisions require that all chromosomes find their homologous partner and achieve recombination and pairing. Sex chromosomes in males of many species have only a small region of homology (the pseudoautosomal region, PAR) that enables pairing. Until recently, little was known about the dynamics of recombination and pairing within mammalian X and Y PARs. Here, we review our recent findings on PAR behavior in mouse meiosis. We uncovered unexpected differences between autosomal chromosomes and the X-Y chromosome pair, namely that PAR recombination and pairing occurs later, and is under different genetic control. These findings imply that spermatocytes have evolved distinct strategies that ensure successful X-Y recombination and chromosome segregation.
authors.affiliation: Molecular Biology Program Developmental Biology Program Howard Hughes Medical Institute, Memorial Sloan-Kettering Cancer Center, New York, New York, USA. KauppiL@mskcc.org
authors.forename: Liisa
authors.initials: L
authors.lastname: Kauppi
authors.forename: Maria
authors.initials: M
authors.lastname: Jasin
authors.forename: Scott
authors.initials: S
authors.lastname: Keeney
mesh_terms: D000818:Animals; D023902:Chromosome Pairing; D022004:Chromosome Structures / Q000235:genetics; D041321:Chromosomes, Human, X; D041322:Chromosomes, Human, Y; D053903:DNA Breaks, Double-Stranded; D005298:Fertility; D042822:Genomic Instability; D006801:Humans; D008540:Meiosis; D012689:Sequence Homology, Nucleic Acid