基于Cyt b序列分析黄沙鳖和日本鳖及其杂交子一代的遗传多样性

Genetic diversity analysis of Pelodiscus sinensis and their hybrid from two geographical populations of using Cyt b sequence

为了解中华鳖(Pelodiscus sinensis)中黄沙鳖和日本鳖及其杂交子一代的遗传特性,分别对它们的线粒体Cytb基因测序,并进行遗传多样性分析。结果表明:PCR扩增测序黄沙鳖和日本鳖及其杂交子一代3个群体共获得90条序列,18种单倍型;90个个体的Cytb基因碱基A、T、C、G平均含量分别为35.4%、26.0%、27.9%、10.7%,表现出明显的反G偏倚;日本鳖、黄沙鳖和杂交鳖分别有5、6、10种单倍型,日本鳖与杂交子代有共享的单倍型Hap 8、Hap 9和Hap 16;3个群体的变异主要存在于群体内部,变异比例为60.8%;3个群体的单倍型多样性为0.747~0.867,平均核苷酸差异数为12.922~16.262,核苷酸多样性为0.00913~0.01151;杂交子一代的单倍型数、单倍型多样性、平均核苷酸差异数、核苷酸多样性均最高,日本鳖的均最低,黄沙鳖、杂交子一代、日本鳖的多态位点数依次降低。可见,杂交子代遗传多样性较高,杂交可提高中华鳖的遗传多样性。

To comprehend the genetic diversity within the Chinese soft-shelled turtle(Pelodiscus sinensis),mitochondrial genes(Cyt b) from two geographical populations of P.sinensis and their hybrids were sequenced and analyzed.The study yielded a total of 90 sequences with 18 haplotypes among the three sequenced groups of Japanese population,Huangsha population and hybrid population of P.sinensis via PCR.Among the 90 individuals of Cyt b,the average base contents for A,T,C and G was 35.4%,26.0%,27.9% and 10.7%,respectively,revealing a distinct anti-G bias.The Japanese population,Huangsha population and hybrid population exhibited 5,6 and 10 haplotypes,respectively.Notably,the Japanese population shared haplotypes Hap 8,Hap 9 and Hap 16 with the hybrid population.Population variance contributed significantly to overall variation at 60.8%.Haplotype diversity for all three populations ranged from 0.747 to 0.867,average nucleotide differences ranged from 12.922 to 16.262,and nucleotide diversity ranged from 0.009 13 to 0.011 51.In terms of the three groups,the number of haplotypes,haplotype diversity,average nucleotide diversity and nucleotide diversity of the hybrid population were the highest,and those of the Japanese population were the lowwest,while the number of polymorphic loci decreased in the order of the Huangsha population,hybrid population and Japanese population.The study findings underscored the rich genetic diversity of hybrid population of P.sinensis,suggesting that hybridization events augment the genetic diversity within P.sinensis.