The first radiation hybrid map of a perch-like fish : The gilthead seabream (Sparus aurata L)

Among Teleosts, Perciformes are the largest order of fishes and include numerous species of commercial importance. Perciformes also comprise species of primary interest for evolutionary studies and analysis of the sex determination systems and sex chromosome plasticity. Unfortunately, genomics tools and resources for Perciformes remain to be developed. Here, we report the production of a seabream whole-genome radiation hybrid (RH) panel in which quality was ascertained by the construction of a 2-Mb-resolution RH map. The map encompasses 440 markers (288 microsatellites, 82 gene-based markers, and 70 STS) suitable for linkage analysis and comparative mapping studies. Achievement of a RHpanel and a whole-genome RH map should contribute to establishing seabream as a fish model among the Perciformes and should be of importance in aquaculture for marker-assisted selection, improvement of growth performance, and disease management. Development of RH maps in a costeffective manner for other fishes with the described methodology will offer a powerful approach in aquaculture and will provide extended capabilities for comparing vertebrate genome evolution. This work was supported by the European Union under Framework Program 5 through the project "Bridge-Map No. Q5RS-2001-01797" coordinated by Georgios Kotoulas (Department of Genetics and Molecular Biotechnology, Institute of Marine Biology of Crete, P.O. Box 2214, Port of Iraklio, Iraklio, Crete, Greece). We acknowledge Francoise Vignaux for providing the CHO HPRT− cell line. We also acknowledge support from the Centre National Recherche Scientifique, the Université de Rennes 1, and the Pole de Calcul Intensif de l'Ouest for technical assistance