人工诱导泥鳅雌核发育的细胞学研究和诱导参数优化
CYTOLOGICAL STUDY ON ARTIFICIALLY INDUCED GYNOGENESIS AND OPTIMIZATION OF INDUCED PARAMETERS IN LOACH, MISGURNUS ANGUILLICAUDATUS
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摘要: 为培育泥鳅(Misgurnus anguillicaudatus)全雌品种, 研究通过细胞荧光染色后进行细胞学观察确定人工诱导泥鳅雌核发育的热休克起始时间, 并进一步利用核型和流式细胞分析等方法对人工诱导雌核发育泥鳅进行鉴定。结果显示, 二倍体泥鳅受到灭活的鲤(Cyprinus carpio)精子刺激后, 第二极体与卵核分开的时间在人工授精后3—5min; 卵子在人工授精后3.5min后再热休克2min的诱导孵化率达到10.26%。通过分析野生型泥鳅胚胎、人工诱导雌核发育泥鳅胚胎、泥鳅×鲤杂交胚胎和单倍体泥鳅胚胎的发育, 发现部分雌核发育的胚胎可以正常发育, 而杂交胚胎和单倍体胚胎会出现明显的发育障碍。核型和流式细胞检测分析表明利用本研究获得的热休克参数进行处理可得到二倍体雌核发育子代, 二倍率达64.71%。研究从细胞学层面获得泥鳅雌核发育的诱导参数, 可为利用人工诱导雌核发育开展全雌泥鳅育种提供指导。Abstract: The female loach (Misgurnus anguillicaudatus) generally have a larger size compared to males. The application of artificially induced gynogenesis in the cultivation of strains presents great potential. In this study, the starting time of heat shock of artificially induced gynogenesis was determined by cytological observation after cell fluorescence staining. The artificially induced gynogeny embryos were further identified by using karyotype and flow cytometric analysis. The results showed that artificial gynogenesis of loach was successfully induced by inactivated common carp sperm. Cytological observation of fertilization showed that the second polar body was observed at 3—5min after insemination. The optimal starting time of heat shock treatment at 41℃ was found to be 3.5min after insemination, followed by a 2min heat shock, resulting in an optimal hatchability rate of 10.26%. By analyzing the development of wild-type loach embryos, artificially induced gynogenetic loach embryos, loach × carp hybrid embryos and haploid loach embryos, it was found that some gynogenetic embryos developed normally, while the hybrid and haploid embryos showed obvious developmental disorders. Karyotype and flow cytometric analysis of the gynogenetic loach embryos further demonstrated that treatment with the heat shock parameters obtained in this study resulted in 64.71% diploid gynogenetic offspring. In this study, the optimized induction parameters of loach meiogynogenesis were obtained through the cytological analysis, which could provide a technical basis for the artificially induced meiogynogenesis in the cultivation of all-female loach strains.