冷休克诱导大鳞副泥鳅雄核发育单倍体

Research on low-temperature induced androgenesis haploid of Paramisgurnus dabryanus

为探索诱导鱼类雄核发育单倍体的新方法及形成机制，以大鳞副泥鳅为研究对象，无须卵子失活，仅用冷休克诱导雄核发育单倍体，并对其后代的早期胚胎发育、染色体数目、分裂胚细胞学观察等进行了系统分析。早期胚胎发育结果显示，0℃与3℃处理组的孵化率分别为0．83％和57．42％，二者之间孵化率差异显著（P〈0．05），0℃和3℃处理组均表现出单倍体综合征。染色体倍性鉴定结果显示，0℃处理组染色体分布为18～27，单倍体率为81．40％，3℃处理组染色体分布为20-30，单倍体率为68．97％。分裂胚细胞学观察结果显示，3℃处理组受精后60min，卵核和第二极体位于胚表面，有一同释放迹象。结果表明，对大鳞副泥鳅受精卵进行3℃冷休克处理60min，可以成功诱导雄核发育单倍体，研究推测冷休克诱导大鳞副泥鳅雄核发育的细胞学机制是雌核和第二极体一同释放。

In this study, in order to explore a new method and formation mechanism of inducing androgenesis haploid,Paramisgurnus dabryanus was treated only by cold-shock without egg inactivation to induce androgenesis haploid, and the early development, chromosome number and cytology observation of embryos were analyzed. Results were as follows：early development of the embryos showed that the hatching rate of the 0 ℃ and 3 ℃ groups was 0.83% and 57.42% respectively,which was significantly different （ P 〈 0.05 ）, and all of them showed haploid syndrome. Ploidy idenfication showed that the chromosome number of the 0 ℃ group ranged from 18 to 27 ,haploid rate was 81.40% , and the chromosome number of the 3 ℃ group ranged from 20 to 30, haploid rate was 68.97%. Cytology observation of the split embryo showed：in the 3 ℃ group,60 min after fertilization, egg nucleus and the second polar body were on the embryo surface, and were about to eliminate together. In conclusion,P, dabryanus androgenesis haploid could be successfully induced when treated at 3 ℃ for 60 rain, and the cytology mechnism may be that the nucleus and the second polar body were spawned together. Results of this study not only enriched the theory of fish sex control, but also provided new way for the all-male production.