长江白甲鱼ITS2序列结构和群体遗传多样性

对长江白甲鱼(Onychostoma sima)样本核DNA进行PCR扩增,获得白甲鱼核DNA上编码核糖体5.8SrRNA和28SrRNA基因的部分序列和完整的ITS2序列(876bp)。运用DNA分析软件对白甲鱼2个驯养群体(重庆水产研究所长寿湖珍稀鱼类繁育中心及涪陵鱼种场)进行了遗传多样性分析。结果表明:该序列平均T、C、A和G碱基组成为22%、32.5%、29.6%和15.8%,颠换Tv=40,转换Ts=10,转换和颠换比值为R=Ts/Tv=0.25。40个体都是单倍型,单倍型多样度为H=1.000,平均核苷酸差异系数K=5.978,核苷酸多样性Pi=0.0682。中性检验及聚类分析表明,两个群体没有分化成单一的群体,两个驯养群体遗传多样性高,种质质量良好。

ITS2 structure and population genetic diversity of Onychostoma sima (Sauvage) in Yangtzi River

Through the PCR amplification of the DNA extracted from the Onychostoma sima samples collected from Yangtze River, the partial sequence of 5.8S and 28S nuclear ribosomal RNA gene and the complete sequence of nuclear ribosomal internal transcribed spacer 2 (ITS2) were obtained. By using the software for DNA analysis, the population genetic diversity of O. sima in the Changshou Lake Rare Fish Breeding Center of Chongqing Fishery Sciences Research Institute and in the Fuling Fish Breeding Center was analyzed. The ITS2 contained 876 bp nucleotides, and the T, C, A, and G were averagely accounted for 22%, 32.5%, 29.6%, and 15.8%, respectively. A total of 50 variable sites were found, including 40 transversions (Tv) and 10 transitions (Ts). The Ts/Tv ratio (R) was 0.25. All the 40 O. sima individuals collected were of 40 haplotypes, the haplotypic diversity (H) was 1.000, the average number of nucleotide differences (K) was 5.978, and the nucleotide diversity (Pi) was 0.0682. Neutrality test and cluster analysis showed the two O. sima populations were not differentiated into a single population. The genetic divergence of the two populations was higher, and their germplasm resources had much higher quality.