Mapping QTL for cold-tolerance trait in a GIFT-derived tilapia line by ddRAD-seq

Tilapia is an economically important fish in the world. High mortality caused by low temperature a serious problem to tilapia farming during overwintering. In this study, genome-wide significant QTL interval, located on chrLG18, controlling cold-tolerance trait was identified full-sib family of GIFT originated line using ddRAD-seq-based mapping. The explained 21.5% phenotypic variances. Six pairs microsatellite markers were successfully developed within interval. For marker SSR613719, which had two genotypes population, ‘lm’ and ‘ll’, number individuals with ‘ll’ genotype significantly higher than cold sensitive population (p < 0.05). This independent test indicated reliability detected QTLs. expression candidate genes (pak1ip1, loc100696456 loc100697261) interval affected under treatment as qRT-PCR test. study provides information for marker-assisted selection tolerant lines.