Plant & Animal Genomes XV Conference

January 13-17, 2007
Town & Country Convention Center
San Diego, CA

Comparative Genomics By Radiation Hybrid Mapping Genes Of The Gilthead Sea Bream Sparus aurata

Elena Sarropoulou¹ , Georgios Kotoulas¹ , Luca Bargelloni² , Deborah M Power³ , Rafaella Franch² , Bruno Louro³ , Antonis Magoulas¹ , Tomasso Patarnello^2,6 , Fabrice Senger⁴ , Francis Galibert⁴ , Robert Geisler⁵

¹  Institute of Marine Biology of Crete, Department of Genetics and Molecular Biotechnology, P.O. Box 2214, 710 03 Iraklio, Crete, Greece

²  Universita di Padova, Dipartimento di Sanita Pubblica, Patologia Comparata e Igiene Veterinaria, 35020 Legnaro, Italy

³  Center for Marine Science (CCMar), Universidade do Algarve, 8000-117 Faro, Portugal

⁴  UMR6061 CNRS, Genetique et Developpement, Faculte de Medecine, 35043 Rennes Cedex, France

⁵  Max-Planck-Institut fuer Entwicklungsbiologie, Abt. III (Genetik), Spemannstrasse 35, 72076 Tuebingen, Germany

⁶  Department of Biology, University of Padova, Padova, Italy

Comparative genomics in teleost fish are of great interest as they are important in aquaculture and in evolutionary issues. One powerful method for comparing genomes of model teleost fish with genomes of farmed teleost fish is comparative mapping. It offers shortcuts for quantitative trait loci (QTL) detections and for studying genome evolution through the identification of regions of conserved synteny. In this study a first approach is reported to comparative mapping by radiation hybrid mapping of the gilthead sea bream Sparus aurata, a teleost fish of commercial and evolutionary interest, as it represents the worldwide distributed species-rich family of Sparidae. A total of 510 genomic anchors were mapped comprising 428 gene-based markers appropriate for comparative mapping studies and 82 microsatellite markers. Data analysis has highlighted synteny and similarity of gene order of sea bream to extensive studied model teleost fish like zebrafish, medaka, and tetraodon and revealed evolutionary conserved regions and regions where breakpoints occurred. It demonstrates the exploitation of this conserved synteny relationships and a one-to-one relationship between Sparus and Tetraodon chromosomes suggesting that three Tetraodon chromosomes correspond to six Sparus radiation hybrid groups as the Tetraodon genome has 21 chromosomes while the genome of Sparus consists of 24 chromosomes. The gene-based anchoring of the radiation hybrid map on the genome maps of model species also pinpoints polymorphic microsatellite markers mapping near genes of interest which control growth, disease resistance, sex determination and reversal, and environmental tolerance, all traits of great importance for QTL mapping and marker assisted selection.