title: Identification of Sex-Linked SNPs and Sex-Determining Regions in the Yellowtail Genome.
abstract: Unlike the conservation of sex-determining (SD) modes seen in most mammals and birds, teleost fishes exhibit a wide variety of SD systems and genes. Hence, the study of SD genes and sex chromosome turnover in fish is one of the most interesting topics in evolutionary biology. To increase resolution of the SD gene evolutionary trajectory in fish, identification of the SD gene in more fish species is necessary. In this study, we focused on the yellowtail, a species widely cultivated in Japan. It is a member of family Carangidae in which no heteromorphic sex chromosome has been observed, and no SD gene has been identified to date. By performing linkage analysis and BAC walking, we identified a genomic region and SNPs with complete linkage to yellowtail sex. Comparative genome analysis revealed the yellowtail SD region ancestral chromosome structure as medaka-fugu. Two inversions occurred in the yellowtail linage after it diverged from the yellowtail-medaka ancestor. An association study using wild yellowtails and the SNPs developed from BAC ends identified two SNPs that can reasonably distinguish the sexes. Therefore, these will be useful genetic markers for yellowtail breeding. Based on a comparative study, it was suggested that a PDZ domain containing the GIPC protein might be involved in yellowtail sex determination. The homomorphic sex chromosomes widely observed in the Carangidae suggest that this family could be a suitable marine fish model to investigate the early stages of sex chromosome evolution, for which our results provide a good starting point.
authors.affiliation: Faculty of Marine Science, Tokyo University of Marine Science and Technology, 4-5-7, Konan, Minato-ku, Tokyo, 108-8477, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Koyama
authors.forename: Akiyuki
authors.initials: A
authors.lastname: Ozaki
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yoshida
authors.forename: Junpei
authors.initials: J
authors.lastname: Suzuki
authors.forename: Kanako
authors.initials: K
authors.lastname: Fuji
authors.forename: Jun-ya
authors.initials: JY
authors.lastname: Aoki
authors.forename: Wataru
authors.initials: W
authors.lastname: Kai
authors.forename: Yumi
authors.initials: Y
authors.lastname: Kawabata
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Tsuzaki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Araki
authors.forename: Takashi
authors.initials: T
authors.lastname: Sakamoto
mesh_terms: D000818:Animals; D016386:Chromosome Walking; D002875:Chromosomes / Q000235:genetics*; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D005260:Female; D008040:Genetic Linkage; D016678:Genome / Q000235:genetics*; D008297:Male; D010473:Perciformes / Q000235:genetics*; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D019849:Sex Determination Processes / Q000235:genetics*; D013045:Species Specificity