Genetic linkage maps of two yellowtails (Seriola quinqueradiata and Seriola lalandi)

The yellowtails Seriola quinqueradiata and Seriola lalandi are the most important species in marine fishery resources and aquaculture in Japan. A genetic linkage map is needed to improve efficiency of breeding by marker-assisted selection (MAS) and for the identification of commercially important genes. Therefore, we have constructed a genetic linkage map for the yellowtails using microsatellite markers. Microsatellites were isolated from a genomic DNA library of S. quinqueradiata. Segregation of 217 microsatellites was studied in 90 progeny from a cross between S. quinqueradiata and S. lalandi. These were used to construct separate linkage maps of a female (S. quinqueradiata) and a male (S. lalandi). Twenty-five linkage groups were distinguished in the female (S. quinqueradiata) map, which spanned for 473.3 centiMorgans (cM) with an average intermarker distance of 2.7 cM (total length estimated: 901.7 cM), and 21 linkage groups were distinguished in the male (S. lalandi) map, which spanned 584.3 cM with an average intermarker distance of 4.8 cM (total length estimated: 1715.3 cM). The microsatellite loci and genetic linkage maps will increase the efficiency of selective breeding programs for yellowtails.