A sex-determining loci in koi carp(Cyprinus carpio) based on whole genome resequencing technology

The recent resolution of the koi carp (Cyprinus carpio) genome framework through high-throughput sequencing has enabled novel insights into sex determination mechanisms. Whole-genome resequencing (WGS) was performed on koi carp, yielding 1,341,975 high-quality SNPs. Integrated analyses, including gene annotation, GO functional classification, and KEGG pathway enrichment, identified four core genes (sox6, wnt7ba, gnrhr4, and mrps30) significantly associated with vertebrate sex-determination pathways. Validation through PCR-RFLP and Sanger sequencing confirmed that SNP3, a sexually dimorphic locus within the exon region of gnrhr4, demonstrated a sex identification accuracy of 100 % (n = 20).This study not only provides a practical molecular marker for sex-controlled breeding but also advances the theoretical understanding of epigenetic regulatory networks underlying sex determination in teleost fishes.