Construction of high-density linkage maps and QTL mapping for growth-related traits in F1 hybrid Yunlong grouper (Epinephelus moara♀ × E. lanceolatus♂)

Abstract

Owing to the increasing market demand and emerging grouper aquaculture industry, close attention has been paid to genetic breeding for growth traits in grouper. The construction of linkage maps for quantitative trait loci (QTL) analyses is an essential step for marker-assisted selection (MAS) programs. In this study, we report the first high-density linkage map of Yunlong grouper (Epinephelus moara♀ × E. lanceolatus♂) constructed by sequencing 118 F1 progenies in a full-sib family using restriction site associated DNA (RAD) technology. For the female and male maps, 12,307 and 12,340 single nucleotide polymorphism (SNP) markers were anchored onto 24 linkage groups, spanning 1909.37 and 1933.61 cM, respectively, with an average marker interval of 0.16 cM. QTL mapping revealed 39 significant QTLs for three growth traits. Candidate genes participating in ubiquitin modification, cell adhesion, G-protein coupled receptors, cell proliferation, and calcium transport were identified from these QTLs, including itgb1, col1a1, pdgfc, bmpr1a, pcdhgc5, and cacna1b. The results of this study provide a foundation for genomic and genetic studies and further analyses of the heterosis of some growth traits, thereby facilitating MAS in Yunlong grouper.