Construction of a microsatellite-based genetic linkage map for half-smooth tongue sole Cynoglossus semilaevis

The half-smooth tongue sole Cynoglossus semilaevis is an important cultured marine fish and a promising model fish for the study of sex determination. Sex-specific genetic linkage maps of half-smooth tongue sole were developed with 567 markers (565 microsatellite markers and two SCAR markers). The parents and F1 progeny (92 individuals) were used as segregating populations. The female map was composed of 480 markers in 21 linkage groups, covering a total of 1388.1 cM, with an average interval 3.06 cM between markers. The male map consisted of 417 markers in 21 linkage groups, spanning 1480.9 cM, with an average interval of 3.75 cM. The female and male maps had 474 and 416 unique positions, respectively. The genome length of half-smooth tongue sole was estimated to be 1522.9 cM for females and 1649.1cM for males. Based on estimations of map length, the female and male maps covered 91.1% and 89.8% of the genome, respectively. Furthermore, two female-specific SCAR markers, f-382 and f-783, were mapped on LG15f (linkage group 15 in female maps). The present study presents a mid-density genetic linkage map for half-smooth tongue sole. These improved genetic linkage maps may facilitate systematic genome searches to identify quantitative trait loci (QTL), such as disease resistance, growth and sex-related traits, and are very useful for marker-assisted selection breeding programs for economically important traits in half-smooth tongue sole [Current Zoology 59 (1):