浅色黄姑鱼线粒体16S rRNA基因片段序列特征分析

PCR扩增100个浅色黄姑鱼个体的线粒体16SrRNA基因片段序列,得到大约620bp的扩增产物。将其中5个个体的扩增产物进行测序和同源比对,得到468bp可供比对分析的片段。比对结果表明,5条序列包括两个单倍型,两个单倍型之间有1个碱基突变。PCR-RFLP分析结果显示,两个种群的100个样品中98%的个体为其中一种单倍型,只有2%的个体呈另一种单倍型,表明这两个种群的遗传多样性较低。两个单倍型平均碱基组成为:T22.0%,C26.3%,A29.8%,G21.9%,GC含量平均为48.2%。与GenBank中石首鱼科7属9种的11条同源序列比对,得到429个比对位点,其中包括69个简约信息位点、55个单突变子和16个插入/缺失位点。聚类分析显示,浅色黄姑鱼与黄姑鱼亲缘关系较近,与形态分类相符。

Sequence analysis of mitochondrial 16S rRNA gene fragment in Chu's croaker (Nibea coibor)

Mitochondrial 16S rRNA gene fragments were amplified from 100 Chu's croaker(Nibea coibor)individuals,the PCR products being about 620bp long.PCR products from five individuals were directly sequenced and aligned subsequently.Then,a fragment of 468bp nucleotide sequence which could be used for sequence analysis was obtained.Five sequences were consisted of two haplotypes,between which there was only one base substitution.The PCR-RFLP analysis showed that 98 % of the 100 individuals from two populations belonged to one haplotype,2 % to another,revealing that genetic diversity in the two populations was fairly low.The average basic compositions of the two haplotypes were as follows:22.0 % T,26.3 % C,29.8 % A,and 21.9 % G,with GC content being 48.2 %.Through alignment with 11 homologous sequences from the other 9 species in 7 genera of Sciaenidae in Genbank,429 aligned sites were obtained,including 69 parsimony-informative sites,55 singletons and 16 insertion/deletions.Phylogenetic analysis demonstrated that Chu's croaker was close to yellow drum(Nibea albiflora)in relativeness,which was consistent with the results by morphological classification.