Identification of breeders’ smQTL and candidate genes associated with growth and fillet quality in Rainbow Trout (Oncorhynchus mykiss) with meta-analysis of QTLs

Rainbow trout ( Oncorhynchus mykiss ) is one of the most frequently farmed cold water fish species. The effective identification of quantitative trait loci (QTL) associated with the growth and fillet quality of rainbow trout can play an effective role in genetic improvement in global aquaculture. In this study, we used the strategy of meta-QTL analysis and identified the position of consensus genetic map markers on the reference genome of rainbow trout, to identify breeders’ sequence based meta-QTLs (sm-QTL). After reviewing QTL studies over the past 22 years, we collected 308 QTLs distributed on 14 chromosomes. Based on the distribution of QTLs related to different studies on each chromosome, six genetic map meta-QTLs (gm-QTL) and four sm-QTL were detected on three chromosomes. Confidence interval (CI) of gm-QTLs decreased on average 6.39 times compared to initial QTLs. The results showed the most promising areas for controlling two traits (breeders’ smQTL) are located on Chromosome 1 and 13. So probably the flanking and interval markers with these genomic regions, have effective applications for marker-assisted selection (MAS). Our study will be effective in investigating diversity and MAS with the aim of molecular breeding of rainbow trout due to the identification of markers close to the consensus of QTLs of growth and fillet quality.