DNA Research Advance Access originally published online on June 25, 2007
DNA Research 2007 14(3):135-140; doi:10.1093/dnares/dsm012
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Short Communication |
Radiation Hybrid Maps of Medaka Chromosomes LG 12, 17, and 22

1 The Graduate School of Frontier Biosciences, Osaka University, 1–3 Yamadaoka, Suita, Osaka 565-0871, Japan
2 SORST Kondoh Research Team, Japan Science and Technology Agency (JST), 14 Yoshida-Kawaracho, Sakyo-ku, Kyoto 606-8305, Japan
3 Department of Biology, Center for Advanced Research in Environmental Genomics, University of Ottawa, 20, Marie Curie, Ottawa, ON, Canada K1N 6N5
4 The Research Institute of the McGill University Health Centre and Department of Surgery, McGill University, Montreal, QC, Canada H3G 1A4
5 Department of Molecular Biology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
6 Department of Integrated Bioscience, Graduate School of Frontier Science, The University of Tokyo, Bioscience Building, 102, Kashiwa, Chiba 277-8562, Japan
7 Max-Planck-Institut für Entwicklungsbiologie, Abteilung III–Genetik, Spemannstrasse 35, Tübingen D-72076, Germany
Received 15 December 2006 ; accepted 8 May 2007.
The Medaka is an excellent genetic system for studies of vertebrate development and disease and environmental and evolutionary biology studies. To facilitate the mapping of markers or the cloning of affected genes in Medaka mutants identified by forward-genetic screens, we have established a panel of whole-genome radiation hybrids (RHs) and RH maps for three Medaka chromosomes. RH mapping is useful, since markers to be mapped need not be polymorphic and one can establish the order of markers that are difficult to resolve by genetic mapping owing to low genetic recombination rates. RHs were generated by fusing the irradiated donor, OLF-136 Medaka cell line, with the host B78 mouse melanoma cells. Of 290 initial RH clones, we selected 93 on the basis of high retention of fragments of the Medaka genome to establish a panel that allows genotyping in the 96-well format. RH maps for linkage groups 12, 17, and 22 were generated using 159 markers. The average retention for the three chromosomes was 19% and the average break point frequency was
33 kb/cR. We estimate the potential resolution of the RH panel to be
186 kb, which is high enough for integrating RH data with bacterial artificial chromosome clones. Thus, this first RH panel will be a useful tool for mapping mutated genes in Medaka.
Key words: Medaka; radiation hybrid mapping; genetic mapping; BAC
* To whom correspondence should be addressed. Tel. +44 (0) 1225 38 5046. Fax. +44 (0) 1225 38 6779. E-mail: furutaniseiki{at}msi.biglobe.ne.jp
Present address: Centre for Regenerative Medicine, Developmental Biology Programme, Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK