应用微卫星多态分析四个鲤鱼群体的遗传多样性

选择12个斑马鱼功能基因的微卫星标记和12个鲤鱼微卫星标记,检测黑龙江鲤(Cyprinus carpiohaematopterusTemminck et Schlegel)、散鳞镜鲤(C.carpio)、荷包红鲤抗寒品系(C.carpiovar.wuyuanensis)、松浦鲤(C.carpioSongpu carp)的群体遗传多样性。共检测到3882个扩增片段,长度为126～489bp,在群体间扩增出1～5个等位基因不等,共计59个等位基因,平均等位基因2.46个。数据经PHYLIP V3.6软件估算和MEGA3软件作图,确立4个群体间的亲缘关系。并应用Bootstrap检验估计系统树中节点的自引导值,并进行了系统发生分析。结果表明①4个群体检测的有效等位基因数都在55个以上,平均观测杂合度为0.36～0.43,平均期望杂合度为0.49～0.53,平均多态信息含量为0.21～0.25,说明这几个群体多态性属于中度偏高水平,遗传多样性较高;②群体间相似系数都在0.84以上,遗传距离较近,为0.067～0.170,与前人研究结果一致。聚类分析显示,松浦鲤与散鳞镜鲤亲缘关系最近,荷包红鲤抗寒品系与它们的亲缘关系较黑龙江鲤更近;③在3个斑马鱼功能基因相关的微卫星位点上,黑龙江鲤缺失特异扩增条带,这可能与几种鱼类的育成史有关。

Microsatellite Variation Among Four Breeding Populations of Common Carps

Using microsatellite markers we determined polymorphism of genomic DNA and classification in four important cultivation species: Common carp (Cyprinus carpio haematopterus Temminck et Schlegel), Scatter scaled mirror carp (C. carpio), Frigid-resistant strain of Purse red carp (C. carpio var. wuyuanensis) and Songpu carp (C. carpio Songpu carp). Amplifications with 24 pairs of primers gave a total of 3 882 fragments ranging from 126 bp to 489 bp in the 4 populations, which included 12 pairs of microsatellites designed according to zebrafish function gene sequences and 12 pairs of microsatellites isolated from common carp. 1-5 alleles per locus in 4 species were amplified, and there were 59 alleles in all populations except common carp which had only 21 loci and 55 alleles. The average number of alleles was 2.46. Additionally, a clustering analysis was made based on the results of the PHYLIP software package (version 3.6) and phylogenetic trees were constructed by MEGA3. The bootstrap values were evaluated for each crunode of the dendrogram by means of 1 000 reiterations of the bootstrap test using the Maximum Likelihood method, the Neighbor-Joining method and the UPGMA method. With these methods we made three observations. (1) the level of genetic variability is relatively high in all populations. Observing value of mean heterozygosity varies from 36.43% to 43.79% and expected value of mean heterozygosity varies from 49.49% to 53.29%. All populations show significant heterozygote deficiencies. (2) The genetic similarity indexes are all above 0.84, indicating closeness of their genetic relationship. The genetic distances are small, ranging from 0.067-0.170. The phylogenetic tree shows that Songpu carp and Scatter scaled mirror carp are the nearest in relationship and Frigid-resistant strain of Purse red carp is better correlated with them than the Common carp. (3) There is no aim fragment amplified in 3 loci of zebrafish function gene microsatellites in the population of common carp, which may mean that the flanking sequence of the microsatellites have changed while the PCR primers were designed according to them or the genomes of common carp have lost these function genes or loci. More research is needed to explore the physiological mechanism and biochemical process. In conclusion, these 24 microsatellite markers can be used for the evaluation of genetic diversity in carps. Three microsatellite markers reveal polymorphism between the common carp and the other three carps, and can be used to distinguish them.