DNA Screening of a sex-specific marker in spotted knifejaw Oplegnathus punctatus and its application

The present invention provides a male-specific DNA marker of Oplegnathus punctatus, wherein the sequence of the DNA fragment on a Y chromosome is shown in SEQ ID NO: 1, and the sequence of the DNA fragment on an X chromosome is shown in SEQ ID NO: 2. The DNA fragment on the Y chromosome is 12 bp more than the fragment on the X chromosome, and the fragment is the DNA fragment peculiar to the Y chromosome. According to the present invention, two homologous and different DNA fragments on the X and Y chromosomes are screened from the whole genome sequence of Oplegnathus punctatus, and a method for identifying the heredity sex of Oplegnathus punctatus is further established. The method can be used for quickly, accurately and effectively distinguishing the heredity sex of Oplegnathus punctatus. The method can amplify a specific target band in a male individual, but cannot amplify a product in a female individual, and the product can be distinguished by agarose electrophoresis. Therefore, the time for accurately identifying the heredity sex of Oplegnathus punctatus is shortened, the method is suitable for identifying the heredity sex of Oplegnathus punctatus in a simple environment of a fish farm, and the detection time and the cost are saved. The method has important significance and application value in sex identification, seed reproduction, and family-selective breeding of Oplegnathus punctatus.