WHOLE GENOME SEQUENCING OF TURBOT: A FISH ADAPTED TO DEMERSAL LIFE

Turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has promoted an active genomic research for a more efficient selection. Obtaining the whole genome of turbot represents an essential landmark for boosting breeding programs and to ascertain their origin and diversification. The turbot genome was compared with model fish to investigate teleost chromosome evolution. A conserved macrosyntenic pattern was observed within Percomorpha and large syntenic blocks identified within the turbot genome related to the teleost genome duplication. Gene family expansions associated with vision and olfactory systems and with antioxidant metabolism of membrane lipids were identified suggesting adaptation to demersal lifestyle and to cold temperatures, respectively. Analysis of gene family expansions in the turbot genome showed an important diversification of flatfish to adapt to benthic life and provides clues for understanding its controversial origin. Moreover, the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and for boosting turbot production, was investigated by mapping candidate genes and reported quantitative trait loci. The genomic architecture of these productive traits led us to identify candidate genes and enriched pathways which represent a useful starting point for future marker assisted selection in turbot.