Plant & Animal Genomes XVI Conference

January 12-16, 2008
Town & Country Convention Center
San Diego, CA

Second-Generation Linkage Map And Comparative Genomics Of European Sea Bass (Dicentrarchus labrax L.)

Dimitry A Chistiakov ^1,2 , Costas S Tsigenopoulos ³ , Gregory E Maes¹ , Erika Souche¹ , Jacques Lagnel ³ , Guo Yuanmei ⁴ , Bart Hellemans ¹ , Chris S Haley ⁴ , Filip AM Volckaert ¹ , Georgios Kotoulas ³

¹  Laboratory of Animal Diversity and Systematics, Katholieke Universiteit Leuven, Charles Deberiotstraat 32, B-3000 Leuven, Belgium

²  Department of Molecular Diagnostics, National Research Center GosNIIgenetika,1st Dorozhny Proezd 1, 113545 Moscow, Russia

³  Hellenic Centre for Marine Research (HCMR) Crete, Institute of Marine Biology and Genetics (IMBG), Thalassocosmos, P.O.Box 2214, Gournes Pediados, 715 00 Heraklion, Crete, Greece

⁴  Roslin Institute (Edinburgh), Roslin, Midlothian EH25 9PS, Scotland, U.K

European sea bass (Dicentrarchus labrax L., Moronidae, Teleostei) sustains a regional fishery and is commonly farmed in the Mediterranean basin but has not been subject to genetic improvement for long. We present a second-generation linkage map and compare the genomes of European sea bass and several model teleosts. An updated genetic linkage map of the European sea bass was constructed, using 246 microsatellites, 221 AFLPs and 2 SNPs. A total of 374 markers were assembled in 35 linkage groups, with 29 groups containing at least 3 mapped markers. Among these markers, 28 represent type I (coding) markers, including those located within the peptide Y, SOX10, PXN1, ERA and TCRB. The sex-averaged map spanned 1373.1 centimorgans (cM) of the genome and included 196 microsatellites, 176 AFLP markers and 2 SNPs. The female map measured 1380.0 cM, whereas the male map measured only 1046.9 cM, leading to a female-to-male (F:M) recombination rate ratio of 1.32:1. Intermarker spacing has decreased from 5.03 to 3.69 cM, making the new map a suitable tool for QTL analysis. Comparative mapping of microsatellite flanking regions with five model teleosts, revealed a high percentage (35.5%) of evolutionnary conserved regions with the three-spined stickleback. Conservation of synteny dropped with phylogenetic distance as analysed in spotted pufferfish, fugu, medaka and zebrafish. Our findings contribute to a better understanding of fish evolution, provide an excellent prospect for enhanced selection in Sea bass aquaculture and open new perspectives towards understanding the effect of natural selection on locally adapted natural populations.