Genome-wide association study reveals molecular markers and genetic basis associated with hypoxia tolerance in...

Hypoxia poses a major threat to the aquaculture industry of darkbarbel catfish, resulting in substantial economic losses for fish farmers. The utilization of molecular markers linked to target traits can improve the efficiency and accuracy of traditional fish breeding. In this study, a genome-wide association study (GWAS) was performed based on whole-genome resequencing data to identify potential single-nucleotide polymorphisms (SNPs) and candidate genes associated with hypoxia tolerance in darkbarbel catfish. A total of 36 SNPs associated with hypoxia tolerance were detected, 17 of which were mapped to linkage group (LG) 25. Combined with Fst scanning analysis, a significantly associated genomic region was identified on LG25, spanning approximately 3.48 Mb from 13,159,434 bp to 16,642,858 bp. Within this region, 37 candidate genes were further annotated, seven of which are involved in the regulation of glycolipid metabolic homeostasis, including scap, klf10, azin1a, srsf10, cthrc1, ptdss1a, and fabp10a. These findings provide novel insights into the genetic basis of hypoxia tolerance in fish and are expected to facilitate the genetic selection and breeding of hypoxia-tolerant in darkbarbel catfish.