title: Gene conversion between the X chromosome and the male-specific region of the Y chromosome at a translocation hotspot.
abstract: Outside the pseudoautosomal regions, the mammalian sex chromosomes are thought to have been genetically isolated for up to 350 million years. However, in humans pathogenic XY translocations occur in XY-homologous (gametologous) regions, causing sex-reversal and infertility. Gene conversion might accompany recombination intermediates that resolve without translocation and persist in the population. We resequenced X and Y copies of a translocation hotspot adjacent to the PRKX and PRKY genes and found evidence of historical exchange between the male-specific region of the human Y and the X in patchy flanking gene-conversion tracts on both chromosomes. The rate of X-to-Y conversion (per base per generation) is four to five orders of magnitude more rapid than the rate of Y-chromosomal base-substitution mutation, and given assumptions about the recombination history of the X locus, tract lengths have an overall average length of approximately 100 bp. Sequence exchange outside the pseudoautosomal regions could play a role in protecting the Y-linked copies of gametologous genes from degeneration.
authors: Department of Genetics, University of Leicester, University Road, Leicester, UK.
authors: Zoë H
authors: ZH
authors: Rosser
authors: Patricia
authors: P
authors: Balaresque
authors: Mark A
authors: MA
authors: Jobling
mesh_terms: D041321:Chromosomes, Human, X; D041322:Chromosomes, Human, Y; D005785:Gene Conversion; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D044469:Racial Groups / Q000235:genetics; D014178:Translocation, Genetic
chemical_list: C109450:PRKX protein, human; C109449:PRKY protein, human; D017346:Protein Serine-Threonine Kinases