The mouse X chromosome is enriched for sex-biased genes not subject to selection by meiotic sex chromosome inactivation

• Published in: Nature genetics Vol. 36; no. 6; pp. 642 - 646
• Main Authors: Khil, Pavel P, Smirnova, Natalya A, Romanienko, Peter J, Camerini-Otero, R Daniel
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01.06.2004; Nature Publishing Group
• Subjects: Agriculture; Animal Genetics and Genomics; Animals; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cancer Research; Chromosomes; Classical genetics, quantitative genetics, hybrids; Datasets; Dosage Compensation, Genetic; Endodeoxyribonucleases; Esterases - deficiency; Esterases - genetics; Female; Females; Fundamental and applied biological sciences. Psychology; Gene Expression; Gene Function; Genetic aspects; Genetics of eukaryotes. Biological and molecular evolution; Genome; Human Genetics; Inactivation; letter; Male; Meiosis - genetics; Mice; Mice, Knockout; Models, Genetic; Ovaries; Physiological aspects; Pregnancy; Sex chromosomes; Spermatogenesis; Spermatogenesis - genetics; Testes; Testis; Vertebrata; X Chromosome - genetics; X chromosomes; United States; New York; United States > US; Vertebrata; Mammalia; Gene; Mouse; Spermatogenesis; Selection; Rodentia; Sex chromosome; Meiosis; X-Chromosome; Inactivation
• ISSN: 1061-4036; 1546-1718
• DOI: 10.1038/ng1368

Sex chromosomes are subject to sex-specific selective evolutionary forces 1 , 2 . One model predicts that genes with sex-biased expression should be enriched on the X chromosome 2 , 3 , 4 , 5 . In agreement with Rice's hypothesis 3 , spermatogonial genes are over-represented on the X chromosome of mice 6 and sex- and reproduction-related genes are over-represented on the human X chromosome 7 , 8 . Male-biased genes are under-represented on the X chromosome in worms and flies 9 , 10 , 11 , 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 12 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.