黄鳝减数分裂雌核发育及子代遗传纯合度分析

INDUCTION OF MEIOGYNOGENESIS IN MONOPTERUS ALBUS AND GENETIC HOMOZYGOSITY ANALYSIS OF THE GYNOGENIC OFFSPRING

为了培育性状优良、遗传稳定的黄鳝(Monopterus albus)群体,研究探索了人工诱导黄鳝减数分裂雌核发育方法。针对养殖性状优良的深黄大斑鳝进行种质纯合,创制出3个深黄大斑鳝雌核发育群体。流式细胞术和染色体计数分析表明雌核发育黄鳝的细胞DNA含量、染色体数目均与野生型相同。性腺组织学切片观察表明雌核发育黄鳝卵巢发育正常。微卫星多样性分析表明雌核发育黄鳝群体的有效等位基因(Ne)、平均香农指数(I)、平均多态信息指数(PIC)、平均观测杂合度(Ho)及平均期望杂合度(He)等参数均极显著低于野生群体,雌核发育群体的遗传纯合度显著提高。雌核发育群体之间的遗传距离增大,遗传相似系数变小。深黄大斑鳝雌核发育群体为培育性状优良的黄鳝养殖品种提供了育种材料。

Swamp eel(Monopterus albus)is an important freshwater culture fish in China and has the characteristic of hermaphroditism and natural sexual reversal.Currently,there is a lack of artificial varieties within swamp eel cultivation,and the fry of mainly rely on the wild catching.Gynogenesis,a method for rapidly obtaining fish population with stable heredity and excellent character,was explored in this study.Meiogynogenesis induction was established in swamp eel,resulting in the creation of three gynogenic populations characterized by deep-yellow coloration.Flow cytometry analysis showed that the cellular DNA contents of gynogenic eels were consistent with those of wild type fish,and chromosome counting confirmed the diploid nature with 48 chromosomes.Histological analysis demonstrated the development of ovaries in the gonads of gynogenic eels,indicating normal diploid functionality.Microsatellite diversity analysis showed that the effective number of alleles(Ne),Shannon’s information index(I),polymorphism information content(PIC),observed heterozygosity(Ho)and expected heterozygosity(He)in gynogenic eels were significantly lower than those in the wild population.The genetic homozygosity in gynogenetic eels exhibited a significant improvement.The genetic distance increased and the genetic similarity decreased between gynogenetic groups.In summary,the gynogenetic population of the deep-yellow swamp eels provides new materials for breeding excellent varieties.