Development and identification of a sex-specific molecular marker in Dai-qu stock large yellow croaker (Larimichthys crocea)

Abstract

Dai-qu stock large yellow croaker (Larimichthys crocea) is an important marine economic fish and geographical population in the East China Sea. Traditionally, large yellow croakers can be divided into three geographical populations as follows: Dai-qu, Min-yuedong and Nao-zhou stocks. In the present study, a sex-specific molecular marker in Dai-qu stock was developed from loci between dmrt1 and cfap157. Based on large yellow croaker genome sequence and a well characterized sex-determining region on chromosome 22, 147 pairs of primers were designed for screening the sex-specific markers by PCR amplification. At last, 1 pair of primers were successfully screened and identified. The results showed that the primers only amplified 500 bp bands in females, whereas, 500 bp bands and 390 bp specific bands were amplified in males. Cloning and sequencing analysis of PCR products showed that females and males share the almost same 500 bp sequence, and the males have a specific deletion of 110 bp than females sequence. 276 individuals of Dai-qu stock large yellow croaker were used to verification this sex-specific marker, and compared with gonadal histological results, the accuracy of the specific primer reached 100%, indicating that the primer can effectively and accurately identify the genetic sex of Dai-qu stock large yellow croaker. In this study, a sex-specific marker was developed and identified, which further verified that the Dai-qu stock large yellow croaker also belonged to XX♀-XY♂ type, providing a useful tool for clarifying the molecular mechanism of sex determination and promoting sex-controlled breeding.