caa a22 4500 463209702 CHVBK 20180405153136.0 cr unu---uuuuu 170326e20071001xx s 000 0 eng 10.1007/s00412-007-0110-z doi (NATIONALLICENCE)springer-10.1007/s00412-007-0110-z Evolution of ZZ/ZW and XX/XY sex-determination systems in the closely related medaka species, Oryzias hubbsi and O. dancena [Elektronische Daten] [Yusuke Takehana, Kiyoshi Naruse, Satoshi Hamaguchi, Mitsuru Sakaizumi] A DM-domain gene on the Y chromosome was identified as the sex-determining gene in the medaka, Oryzias latipes, and named DMY (also known as dmrt1bY). However, this gene is absent in most Oryzias fishes, suggesting that closely related species have another sex-determining gene. In fact, it has been demonstrated that the Y chromosome in O. dancena is not homologous to that in O. latipes, whereas both species have an XX/XY sex-determination system. Through a progeny test of sex-reversed fish and a linkage analysis of isolated sex-linked DNA markers, we show that O. hubbsi, which is one of the most closely related species to O. dancena, has a ZZ/ZW system. In addition, genetic and fluorescence in situ hybridization mapping of the sex-linked markers revealed that sex chromosomes in O. hubbsi and O. dancena are not homologous, indicating different origins of these ZW and XY sex chromosomes. Furthermore, we found that O. hubbsi has morphologically heteromorphic sex chromosomes, in which the W chromosome has 4,6-diamidino-2-phenylindole (DAPI)-positive heterochromatin blocks and is larger than the Z chromosome, although such differentiated sex chromosomes have not been observed in other Oryzias species. These findings suggest that a variety of sex-determining mechanisms and sex chromosomes have evolved in Oryzias. Springer-Verlag, 2007 Takehana Yusuke Graduate School of Science and Technology, Niigata University, Nishi-ku, 950-2181, Niigata, Japan aut Naruse Kiyoshi Laboratory of Bioresources, National Institute for Basic Biology, 444-8585, Okazaki, Japan aut Hamaguchi Satoshi Graduate School of Science and Technology, Niigata University, Nishi-ku, 950-2181, Niigata, Japan aut Sakaizumi Mitsuru Graduate School of Science and Technology, Niigata University, Nishi-ku, 950-2181, Niigata, Japan aut Chromosoma Springer-Verlag 116/5(2007-10-01), 463-470 0009-5915 116:5<463 2007 116 412 https://doi.org/10.1007/s00412-007-0110-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00412-007-0110-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Takehana Yusuke Graduate School of Science and Technology, Niigata University, Nishi-ku, 950-2181, Niigata, Japan aut NATIONALLICENCE 700 1- Naruse Kiyoshi Laboratory of Bioresources, National Institute for Basic Biology, 444-8585, Okazaki, Japan aut NATIONALLICENCE 700 1- Hamaguchi Satoshi Graduate School of Science and Technology, Niigata University, Nishi-ku, 950-2181, Niigata, Japan aut NATIONALLICENCE 700 1- Sakaizumi Mitsuru Graduate School of Science and Technology, Niigata University, Nishi-ku, 950-2181, Niigata, Japan aut NATIONALLICENCE 773 0- Chromosoma Springer-Verlag 116/5(2007-10-01), 463-470 0009-5915 116:5<463 2007 116 412 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer