秀丽白虾3个地理种群mtDNA 16S rRNA基因序列变异及遗传分化

Sequence variations and genetic differentiations in 16S rRNA gene in three geographic populations of Siberian prawn Exopalaemon modestus

为探究秀丽白虾Exopalaemon modestus不同地理种群的遗传变异,采用PCR产物纯化测序的方法,分别测定了太湖、鄱阳湖和兴凯湖3个种群共计129个秀丽白虾样品的mtDNA 16S rRNA基因序列。结果表明:在486 bp序列中,检测到10个变异位点,占所测序列的2.06%;共发现8种单倍型,其中太湖种群5种,鄱阳湖种群4种,兴凯湖种群1种;单倍型Ⅰ为太湖和鄱阳湖种群共有,单倍型Ⅳ为鄱阳湖和兴凯湖种群共有,3个种群未有共享单倍型;平均单倍型多样性(Hd)和核苷酸多样性(Pi)分别为0.691 00和0.002 46,遗传多样性较低;AMOVA分析显示,3个种群间的遗传变异为29.58%,种群内的遗传变异为70.42%,遗传分化系数(Gst)为0.295 8,基因流(Nm)为0.595 2,3个种群间遗传分化存在极显著性差异(P<0.01)。本研究结果可为秀利白虾种质资源保护提供基础数据。

Purified PCR products were sequenced and part sequences of mitoehondrial 16S rRNA gene were ob- tained in 129 individuals of Siberian prawn Exopalaemon modestus collected from Taihu Lake, Poyanghu Lake and Xingkaihu Lake among three geographic populations of Siberian prawn in order to study genetic variations in Siberi- an prawn. The results showed that 10 variable sites （2.06% of total nueleotides）were found in 486 bp fragment, and that 8 haplotypes were observed by analysis of haplotypes, including 5 haplotypes in Taihu Lake population, 4 ones in Poyanghu Lake population and Ⅰ one （Hapiv） in Xingkaihu Lake population. Hap Ⅰ was shared by popula- tions from Taihu Lake and Poyanghu Lake, Hap Ⅳ was shared by populations from Poyanghu Lake and Xingkaihu Lake, and no haplotype was shared by all the populations. There was average haplotype diversity （Hd） of 0.691 00 and the nueleotide diversity （Pi） of 0.002 46, indicating low genetic diversity in the three populations. Analysis of molecular variance （AMOVA） revealed that genetic variation was 70.42% within the populations and the genetic variation of 29.58% among three populations, with genetic differentiation index （Gst） of 0.295 8 and gene flow （Nm） of 0.595 2, indicating that there was vecy significant genetic differentiation among three populations （P〈 0.01 ）. The findings provide basic data for germplasm conservation of Siberian prawn.