process of a Y-loss event in an XO/XO mammal, the Ryukyu spiny rat

• Published in: Chromosoma Vol. 119; no. 5; pp. 519 - 526
• Main Authors: Kuroiwa, Asato, Ishiguchi, Yasuko, Yamada, Fumio, Shintaro, Abe, Matsuda, Yoichi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.10.2010; Springer-Verlag; Springer Nature B.V
• Subjects: Animal Genetics and Genomics; Animals; Base Sequence; Biochemistry; Biomedical and Life Sciences; Cell Biology; Chromosome Mapping; Cytogenetic Analysis; Developmental Biology; DNA-Binding Proteins - genetics; Eukaryotic Microbiology; Female; Gene Expression; Genes, sry; Genes, X-Linked; Genes, Y-Linked; Human Genetics; Humans; In Situ Hybridization, Fluorescence; Life Sciences; Male; Meiosis; Mice; Murinae - genetics; Nuclear Proteins - genetics; Pseudogenes; Research Article; Sex Chromosome Aberrations; Sex-Determining Region Y Protein - genetics; Spermatogenesis; Translocation, Genetic; X Chromosome - genetics; Y Chromosome - genetics; Y Chromosome - ultrastructure; Takara Biomedical; Mouse Genome Informatics; H3K4 Demethylase Activity; Saline Sodium Citrate; Mouse cDNA Clone
• ISSN: 0009-5915; 1432-0886
• DOI: 10.1007/s00412-010-0275-8

The Ryukyu spiny rat, Tokudaia osimensis, has an XO/XO sex chromosome constitution, lacking a Y chromosome and the mammalian sex-determining gene SRY. To investigate the Y-loss event, we traced three proto-Y-linked genes, RBMY1A1, EIF2S3Y, and KDM5D, in the genome. The original Y-linked RBMY1A1 was lost as well as SRY, and the remaining RBMY1A1 was a processed pseudogene on autosome. In contrast, EIF2S3Y and KDM5D were conserved in genomes of both sexes as a result of their translocation from the Y chromosome to the X chromosome and/or autosomes. Furthermore, these genes were expressed in gonads and brains of both sexes. Our study indicated a loss of Y-linked genes with important male functions to be necessary for the Y chromosome to disappear. These functions might have been retained through the acquisition of new genes, and therefore, the Y-loss has had no harmful effect on the maintenance of this species.