【摘要】 利用核糖体DNA转录间隔区ITS-1序列对硬壳蛤(Mercenaria mercenaria)的养殖群体和青蛤(Cyclinasinensis)的野生种群遗传多样性进行了分析.经过PCR扩增、连接与测序后,得到硬壳蛤ITS-1的长度为718～724 bp,青蛤的为665～683 bp,序列用ClustalX1.83多重比对后,在725 bp组成的同源片段中有714个碱基序列为保守位点,通过DNAsp软件分析,该种群的核酸多态性指数Pi为0.00302,每位点Eta为0.00304,并检测出4个单倍型(Haplotype)序列.青蛤在由695 bp组成的同源片段中有644个碱基序列为保守位点,该种群的Pi为0.03071,每位点Eta为0.0378,共测出6个单倍型(Haplotype)序列.利用PAUP4.10软件计算出每个种群内单倍型序列间的相对遗传距离,其中,硬壳蛤的遗传距离仅为0.0014～0.0056,说明其DNA遗传多样性的丰度较低;而野生青蛤种群的遗传距离为0.0036～0.0105,说明其遗传多样性比较丰富.文章还初步讨论了双壳类遗传多样性变动的因素及种质保护等问题.更多还原

【Abstract】 The genetic diversity of cultured Mercenaria mercenaria and wild Cyclina sinensis populations was investigated by using the ribosome DNA gene interval transcribed spacers1(ITS-1)sequences.After PCR amplification,ligation and sequencing,the ITS-1 sequences of M.mercenaria and C.sinensis obtained from individuals of populations ranged in 718～724 and 665～683 nucleotides in length,respectively.By alignment with Clustal-X,725 homologous sites in ITS-1 fragment of M.mercenaria had 714 monomorphic sits.Its nucleotide diversity Pi=0.003 02,Theta(per site) Eta=0.003 04, and 4 haplotypes were identified from the population,analyzing the sequences variations with DNAsp4.695 homologous sites in fragment of C.sinensis had 644 monomorphic sits.Its Pi= 0.030 71,Eta=0.037 8 and 6 haplotypes were identified from population.The pairwise genetic distance matrix of haplotypes was produced by PAUP 4.10 beta following the method of Hasegawa,et al(1985) to evaluate the ratios of transition/transversion in nucleotides.The results showed that the genetic distance among haplotypes of M.mercenaria and C.sinensis were 0.001 4 to 0.005 6 and 0.003 6 to 0.010 5 respectively,the later of index is much higher than the former.The influencing factors of genetic diversity in the populations and the conservation of idioplasm were also discussed.更多还原