A genetic linkage map of kelp grouper (Epinephelus bruneus) based on microsatellite markers

Kelp grouper (Epinephelus bruneus) is an important aquaculture species in Japan, Korea and China. Mariculture production of the species has increased due to its high demand and market price. However, some problems affect kelp grouper aquaculture such as the low growth rate, high mortality due to diseases and low ability to survive the larval stage. To analyze economically important traits, genetic linkage maps are an effective tool. We constructed sex-specific linkage maps of kelp grouper using 222 microsatellite markers. The male map consisted of 23 linkage groups with 161 markers and the female map consisted of 25 linkage groups with 173 markers. The total lengths of the male and female maps were 650.5cM and 944.4cM, respectively, and the average intervals were 5.0cM and 6.7cM, respectively. The average ratio of recombination between males and females was 1:1.5. Moreover, syntenic sequence comparisons provided basic information of several potential candidate genes affecting organism physiological and biochemical reactions. Based on the linkage map, further quantitative trait loci (QTL) or candidate gene(s) detection can be anticipated to contribute to assist breeding programs of kelp grouper. In addition, by providing basic genome information of kelp grouper, the map provides a first step towards comparative QTL as well as comparative genome analyses with other groupers in the future. •We constructed linkage maps of kelp grouper using 222 microsatellite markers.•The male map consisted of 23 linkages, and the female map consisted of 25 linkages.•Kelp grouper has an advantage to study the reason for a protogynous hermaphrodite.•This map is the first linkage map in the subfamily Epinephelinae.•This map will assist breeding programs of kelp grouper.