title: The mouse X chromosome is enriched for sex-biased genes not subject to selection by meiotic sex chromosome inactivation.
abstract: Sex chromosomes are subject to sex-specific selective evolutionary forces. One model predicts that genes with sex-biased expression should be enriched on the X chromosome. In agreement with Rice's hypothesis, spermatogonial genes are over-represented on the X chromosome of mice and sex- and reproduction-related genes are over-represented on the human X chromosome. Male-biased genes are under-represented on the X chromosome in worms and flies, however. Here we show that mouse spermatogenesis genes are relatively under-represented on the X chromosome and female-biased genes are enriched on it. We used Spo11(-/-) mice blocked in spermatogenesis early in meiosis to evaluate the temporal pattern of gene expression in sperm development. Genes expressed before the Spo11 block are enriched on the X chromosome, whereas those expressed later in spermatogenesis are depleted. Inactivation of the X chromosome in male meiosis may be a universal driving force for X-chromosome demasculinization.
authors.affiliation: Genetics and Biochemistry Branch, NIDDK, National Institutes of Health, 5 Memorial Drive, Bethesda, Maryland 20892, USA.
authors.forename: Pavel P
authors.initials: PP
authors.lastname: Khil
authors.forename: Natalya A
authors.initials: NA
authors.lastname: Smirnova
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Romanienko
authors.forename: R Daniel
authors.initials: RD
authors.lastname: Camerini-Otero
mesh_terms: D000818:Animals; D004303:Dosage Compensation, Genetic; D004706:Endodeoxyribonucleases; D004950:Esterases / Q000172:deficiency / Q000235:genetics; D005260:Female; D015870:Gene Expression; D016678:Genome; D008297:Male; D008540:Meiosis / Q000235:genetics*; D051379:Mice; D018345:Mice, Knockout; D008957:Models, Genetic; D011247:Pregnancy; D013091:Spermatogenesis / Q000235:genetics; D014960:X Chromosome / Q000235:genetics*; D000099257:Meiotic Recombination Protein SPO11
chemical_list: D004706:Endodeoxyribonucleases; D004950:Esterases; D000099257:Meiotic Recombination Protein SPO11