X-chromosomal localization of mammalian Y-linked genes in two XO species of the Ryukyu spiny ratArakawa Y. · Nishida-Umehara C. · Matsuda Y. · Sutou S. · Suzuki H.
aLaboratory of Ecology and Genetics, Graduate School of Environmental Earth Science, bLaboratory of Animal Cytogenetics, Center for Advanced Science and Technology, cChromosome Research Unit, Faculty of Science, Hokkaido University, Sapporo; and dFunctional Genomics, School of Pharmacy, Shujitsu University, Okayama (Japan)
Ryukyu spiny rats (genus Tokudaia), which are endemic to the central part of the Nansei Shoto archipelago in Japan, have unique karyotypes with odd numbers of chromosomes and no cytologically recognizable Y chromosome. The chromosome numbers of Tokudaia osimensis from Amamioshima and of Tokudaia sp. from Tokunoshima are 2n = 25 and 2n = 45, respectively, with a putative single X chromosome. The mouse X probe hybridized to the unpaired X chromosome, except for the distal part of the short arm in a female specimen of T. osimensis and in one male and one female of Tokudaia sp. Fluorescence in situ hybridization with the Tspy (testis-specific protein, Y-encoded) gene from both male and female cells of Tokudaia sp. by PCR localized Tspy to the distal part of the long arm of the X chromosome. Another Y-related gene, Zfy, from Tokudaia sp. was also localized to the same region in both species. Although the Sry gene is absent in this species, the present results suggest that the Y-chromosome segment carrying functional Y-linked genes, such as Tspy and Zfy, is translocated onto the distal part of the long arm of the X chromosome.
Request reprints from Dr. Hitoshi Suzuki
Laboratory of Ecology and Genetics
Graduate School of Environmental Earth Science, Hokkaido University
North 10, West 5, Kita-ku, Sapporo 060-0810 (Japan)
telephone: +81-11-706-2279; fax: +81-11-706-2225
Supported in part by grants-in-aid for scientific research from the Ministry of Education, Science, Sports and Culture, Japan, and in part by a grant from the Environment Agency of the Government of Japan. Y.A. and C.N.-U. contributed equally to this work.
Received 17 December 2002;
manuscript accepted 6 February 2003.
Number of Print Pages : 7
Number of Figures : 6, Number of Tables : 0, Number of References : 31
Cytogenetic and Genome Research
Formerly ‘Cytogenetics and Cell Genetics’
Vol. 99, No. 1-4, Year 2002 (Cover Date: 2002)
Journal Editor: H.P. Klinger, Bronx, N.Y.; M. Schmid, Würzburg
ISSN: 1424–8581 (print), 1424–859X (Online)
For additional information: http://www.karger.com/journals/cgr