European Sea Bass

Abstract

Aquaculture of European sea bass (Dicentrarchus labrax L.) has taken off in the coastal regions of the Mediterranean Sea and southeastern Atlantic Ocean over the past 25 years and increased to 71,649 metric tons in 2004. Genetic support for this industry was initially limited to cytogenetics and population genetics, but with time it has been complemented with selective breeding, as well as functional and comparative genomics. The haploid genome of sea bass consists of 24 chromosomes, weighing 0.78 pg and containing approximately 1,525 Mb. A number of different types of genetic markers are available. A first-generation linkage map based on 174 microsatellite markers covers 25 linkage groups (815 cM). A draft of an updated linkage map, including 369 microsatellite and AFLP markers, is now available. EST resources based on at least 17 cDNA tissue libraries and surpassing 30,000 sequence traces have been generated. A large insert BAC library has a 13× genomic coverage. Breeding goals have been established and heritability values of various traits measured. Functional genomic analysis in relation to the reproductive biology and stress physiology are in progress. A pilot analysis has detected a QTL for body length on the terminal end of linkage group 1. All these resources bring European sea bass into the group of the top ten genome resource-rich fish species. Additional genomic resources such as EST sequences, macro- and micro-arrays, a second-generation linkage map, and physical maps based on BAC fingerprints and radiation hybrids will become available in the near future. Selective breeding of this species is expected to direct it progressively toward complete domestication.