A PCR-based genetic sex identification method in spotted mandarin fish (Siniperca scherzeri) and big eye mandarin fish (Siniperca kneri)

Abstract Sex-specific markers are extremely important for unisexual breeding and understanding of sex determination mechanisms. Spotted mandarin fish (Siniperca scherzeri) and big eye mandarin fish (Siniperca kneri) are economically important freshwater fish in China. Here, for the first time, we successfully identified three male-specific markers in the two species. Through genome sequencing and bioinformatic analysis of three males, three females, one male mixed pool and one female mixed pool of spotted mandarin fish, we screened 27 potential male-specific sequences. After PCR validation, three male-specific markers were further identified. Moreover, these markers could also be used to identify genetic sex of spotted mandarin fish from different populations with 100 % accuracy. In addition, these markers were also successfully used in the identification of genetic sex of big eye mandarin fish. Notably, the sequences of male-specific markers were highly similar in the two species and the corresponding sequence of one marker was highly similar to partial genome sequence of amhy gene in mandarin fish (Siniperca chuatsi). In all, the verified male-specific markers suggested XY sex determination system existed in spotted mandarin fish and big eye mandarin fish and would play an important role in future work of sex control breeding.