Guangdong nongye kexue (Feb 2024)
Inspiration of Sex Regulation in Teleosts on Sex Reversal of Zig-zag Eel (Mastacembelus armatus)
Abstract
Influenced by two mechanisms of genetic sex determination and environmental sex determination, the sex control of fish is of great significance for aquaculture. Compared with other vertebrates, fishes exhibit great plasticity in sex differentiation and gonadal development. There are significant differences in the size and growth rate of male and female teleosts. Cultivating and breeding large and fast-growing unisexual populations is beneficial to improve economic benefits. Mastacembelus armatus is a kind of freshwater aquaculture fish with high nutritional and economic values. Male individuals grow faster and have a larger body size than females, therefore, cultivating all-male M. armatus has higher economic benefits.In the wild environment, the male to female ratio of the M. armatus is approximately 1∶1, however, there is a high female rate under artificial breeding conditions. At present, it has not been clear what factors cause the feminization of M. armatus, and there have been no successful reports of inducing physiological female sex reversal in the M. armatus, which greatly restricts the development of the M. armatus breeding industry and the improvement of economic benefits. At present, researches on the M. armatus mainly focus on morphology, physiology, reproductive biology, genetic diversity, and other aspects. The research on sex determination and differentiation of the M. armatus is relatively weak, and it is necessary to explore ideas from the sex determination mechanisms, sex regulation methods and sex control breeding techniques of other teleosts. Based on the mechanism of sex determination in teleosts, and the review summarizes several ways of sex control in teleosts, mainly including genetic factors regulation like sex determining genes on sex chromosomes and autosomes, as well as environmental factors regulation, such as temperature, exogenous hormones and fish feed. It aims to provide ideas for analyzing the causes and potential mechanism forhigh feminization of artificial cultivation of the M. armatus, and to provide important theoretical basis for the reproduction and maintenance of unisexual populations, the selection of excellent varieties, and the protection of germplasm resources of the M. armatus, to better understand the gonadal development and reproductive mechanism of the M. armatus, solve the bottleneck of low male rate in currently cultivated M. armatus and provide guarantees for the sustainable development of the M. armatus aquaculture industry.
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