Unveiling potential sex-determining genes and sex-specific markers in autotetraploid Carassius auratus

Autotetraploid Carassius auratus is a stable hereditary autotetraploid fish resulting from the hybridization of Carassius auratus red var.(RCC,♀)×Megalobrama amblycephala(BSB,♂),containing four sets of RCC chromosomes.However,the molecular mechanism underlying the determination of sex in this species remains largely unknown.Currently,there lacks a full understanding of the molecular mechanisms governing sex determination and specific molecular markers to differentiate sex in this species.In this study,25,801,677 SNPs(Singlenucleotide polymorphism)and 6,210,306 Indels(insertion-deletion)were obtained from whole-genome resequencing of 100 individuals(including 50 female and 50 male).Further identification confirmed the candidate chromosomes as Chr46B,with the sex-determining region located at Chr46B:22,500,000‒22,800,000 bp.Based on the male-specific insertion(26 bp)within the candidate sex-determining region,a pair of sex-specific molecular markers has been identified.In addition,based on the screening of candidate sex-determining region genes and RT-qPCR validation analysis,ADAM10,AQP9 and tc1a were identified as candidate sex-determining genes.These findings provide a robust foundation for investigating sex determination mechanisms in fish,the evolution of sex chromosomes,and the development of monosex populations.

Sex Identification of Red-crowned Crane by the Polymerase Chain Reaction

Sex determining gene primers of Oriental White Stork were used to amplify sex-linked gene of the Red-crowned Crane′s W chromosome-specific by PCR for sex identification. The sexes of 7 couples of grown Red-crowned Cranes and 15 youngs were identified. Through DNA sequence analysis, the identity is 94.77% between Red-crowned Crane and Oriental White Stork. The results of this study suggest that the application of the polymerase chain reaction technique is practicable for determining sex in the Red-crowned Crane.

Progress in research on fish sex determining genes

Research on fish sex determining genes and their mode of action is not only important for elucidating the mechanisms of vertebrate sex determination,but also for fish monosex control breeding.This paper briefly summarizes our current knowledge about vertebrate sex determination,and reviews the progress of research on fish sex determining genes,including their function and their mechanism of action.In recent years,the number of newly uncovered fish sex determining genes has grown rapidly.In contrast,no sex determining genes have been identified in Cyprinid fishes,which constitute most of the aquaculture fish species in China.Technologies such as high-throughput sequencing and gene editing will provide important technical support for the study of sex determining genes in fish,and play an important role in establishing accurate sex-controlling breeding techniques and the creation of new fish germplasm.