Identification of male-specific SNP markers and development of rapid PCR-based genetic sex identification method in channel catfish (Ictalurus punctatus)

Abstract

Channel catfish (Ictalurus punctatus) is an important aquaculture species worldwide. Although studies of the sex determination mechanism of channel catfish began during the 1980s, the mechanism and sex-specific genes remain unclear. In this study, based on the results of sex-related quantitative trait locus (QTL) mapping and targeted next-generation sequencing (NGS) technique, 13 male-specific single nuclear polymorphisms (SNPs) were identified in the coding region of the zbtb38 gene of channel catfish by targeted next-generation sequencing. Among them, six substitutions resulted in changes in the amino acid coding in zbtb38 on both the X and Y chromosomes. It is speculated that zbtb38 on the Y chromosome has an important role in testicular differentiation and is an important candidate gene for sex determination in channel catfish. Subsequently, male-specific primers were designed according to male-specific nucleotides, which amplified an expected band from males but not from females. Thus, a rapid and effective method was successfully established to identify the genetic sex of channel catfish. Our study contributes to the study of the sex determination mechanisms and development of mono-sex populations in channel catfish.