title: Sex chromosomes and male functions: where do new genes go?
abstract: The position of a gene in the genome may have important consequences for its function. Therefore, when a new duplicate gene arises, its location may be critical in determining its fate. Our recent work in humans, mouse, and Drosophila provided a test by studying the patterns of duplication in sex chromosome evolution. We revealed a bias in the generation and recruitment of new gene copies involving the X chromosome that has been shaped largely by selection for male germline functions. The gene movement patterns we observed reflect an ongoing process as some of the new genes are very young while others were present before the divergence of humans and mouse. This suggests a continuing redistribution of male-related genes to achieve a more efficient allocation of male functions. This notion should be further tested in organisms employing other sex determination systems or in organisms differing in germline sex chromosome inactivation. It is likely that the selective forces that were detected in these studies are also acting on other types of duplicate genes. As a result, future work elucidating sex chromosome differentiation by other mutational mechanisms will shed light on this important process.
authors.affiliation: Department of Biology, University of Texas at Arlington, Arlington, Texas, USA.
authors.forename: Esther
authors.initials: E
authors.lastname: Betrán
authors.forename: J J
authors.initials: JJ
authors.lastname: Emerson
authors.forename: Henrik
authors.initials: H
authors.lastname: Kaessmann
authors.forename: Manyuan
authors.initials: M
authors.lastname: Long
mesh_terms: D000818:Animals; D004330:Drosophila / Q000196:embryology / Q000235:genetics; D019143:Evolution, Molecular; D018095:Germ-Line Mutation / Q000235:genetics*; D006801:Humans; D008297:Male; D019849:Sex Determination Processes; D012733:Sex Differentiation / Q000235:genetics*; D013091:Spermatogenesis / Q000235:genetics; D014960:X Chromosome / Q000235:genetics*; D049951:X Chromosome Inactivation / Q000235:genetics