大鲵2个驯养群体ITS2遗传多样性分析

对大鲵(Andrias davidianus)2个驯化种群的核DNA进行PCR扩增,获得大鲵核DNA上编码核糖体5.8S rRNA和28S rRNA基因的部分序列和完整的ITS2序列(606 bp)。运用DNA分析软件对大鲵2个驯养种群(重庆水产研究所长寿湖珍稀鱼类繁育中心及广汉珍稀鱼类养殖公司)进行了遗传多样性分析。结果显示,该序列平均T、C、A、G含量分别为15.6%、36.5%、12.5%和35.4%,其中G、C的含量C+G(平均为71.9%)显著高于A、T含量A+T(平均为28.1%)。所测序列中有271个碱基发生颠换,112个碱基发生转换,转换与颠换比值(Si/Sv)为0.41,颠换大于转换。10个体均为单倍型,单倍型多样度(H)均为1.000 0±0.126 0,平均核苷酸差异系数(K)为5.932 1±0.861 4,核苷酸多样性(Pi)为0.631 9±0.013 9。种群遗传分化度(Fst)为0.030 5,中性检验及聚类分析表明2个群体没有分化成单一的群体,2个驯养种群遗传多样性好。

Analysis of ITS2 genetic diversity between two acclimation populations of Chinese giant salamander, Andrias davidianus

The nuclear DNA of two populations of Andrias davidianus was amplified by PCR.The amplified fragments including 5.8S and 28S nuclear ribosomal RNA gene partial sequence and the nuclear ribosomal second internal transcribed spacer(ITS2) complete sequence.The length of the fragment contained 606 bp nucleotides.The genetic diversities of Andrias davidianus from the Changshou Lake Rare Fish Breeding Center(CSLRFBC) of the Chongqing Fisheries Research Institute and Guanghan Rare Aquaculture Company(GHRAC) were ana-lyzed.The result indicated as follows.The T,C,A and G average contents were 15.6%,36.5%,12.5% and 35.4% respectively.The average contents of G+C and A+T were 71.9% and 28.1% respectively.The average values of transversional pairs were 271 and transitional pairs were 112.The ratio of transition and transversion was 0.41,and the ratio of transversion exceeded that of transition significantly.The 10 individuals belonged to 10 haplo-types according to the determined sequences.The haplotypic diversity(H) was 1.0000±0.1260,and the average number of nucleotide differences(K) of them was 5.9321±0.8614.The nucleotide diversity(Pi) of the 10 indi-viduals was 0.6319±0.0139.The correlation within populations relative to total was 0.0305 to the two popula-tions.Two populations have not differentiated to a single population by test of Tajima,s D,Fu&Li,s D,F and clus-ter analysis.