中国大头蛙属3个种线粒体ND1基因全序列分析与亲缘关系

Sequence of Mitochondrial NADH Dehydrogenase Subunit 1(ND1)Gene Of L.kuhlii and L.fragilis,and the Phylogenetic Relationships among 3 Chinese Species of Limnonectes

测定了大头蛙和脆皮大头蛙线粒体ND1基因全序列长度分别为978 bp和958 bp,(对应编码325和319个氨基酸)。对所测基因序列组分进行了分析,并与福建大头蛙同源序列进行比较发现,978个核苷酸位点中,有664个保守位点和多变位点294个。同时发现福建大头蛙与大头蛙该基因序列的同源性最高(核苷酸序列同源性为78.77%,氨基酸序列为92.62%)。基于ND1基因全序列的氨基酸和核苷酸两种数据形式,选用M ega3.1软件中的NJ法对大头蛙属3个种、黑斑蛙、泽陆蛙及外群中国大鲵共6条基因序列进行系统树重建分析,结果表明:所得的2个NJ树均将大头蛙属3个种聚于一支,其中大头蛙与福建大头蛙为姐妹群关系(自检值均高度支持),从而证实了大头蛙与福建大头蛙亲缘关系较近的观点。

The complete sequences of mitochondrial NDI genes were determined for L. kuhlii and L. fiagilis. Two sequences were deposited in GenBank （accession No. AY899241 and AY899242 ）. The authors aligned the NDI gene sequences of them and L. fujianensis （ the published sequence in GenBank, AY974191 ） using Clustal X software program. By comparing three sequences of Limnonectes, the divergences and base substitutions among these sequences were analyzed with the MEGA3. 1 software. The alignment of the NDI gene contained 978 nucleotide positions with gaps, including 664 constant sites and 294 variable sites. The NDI gene sequence of L. kuhlii showed minor differences （92.62 % similarity at the amino acid level and 78.77% similarity at the nucleotides level） to the homologous sequence of L. fujianensis mt DNA. To further confirm the Phylogenetic relationships among 3 Chinese species of Limnonectes, another 2 mt NDI genes of frogs （ F. limnocharis and R. nigromaculata） were retrieved from GenBank, the salamander （Andrias davidianus, AJ492192） was used the outgroup species. DNA molecular phylogenies were derived using MEGA3.1, with neighbor-joining analyses, based on the amino acid sequence and the nucleotides sequences data. respectively. The phylogenetic analyses results show that two trees of NJ both strongly support a monophyletic group of 3 Chinese species of Limnonectes and a sister group relationship for L. kuhlii and L. fujianensis. A close relationship between L. kuhlii and L. fujianensis was confired.