盘丽鱼属鱼类线粒体DNA细胞色素b基因序列和亲缘关系分析

通过测定盘丽鱼属鱼类绿盘丽鱼(S.aequifasciataaequifasciata)、褐盘丽鱼(S.aequifasciataaxelrodi)和盘丽鱼(S.discus)线粒体DNA细胞色素b(mtDNAcytb)基因全序列,结合对GenBank中蓝盘丽鱼(S.aequifasciataharaldi)该序列的比较分析,共检测到23个变异位点,占全序列的2.02%,其中22个为转换,1个为颠换,碱基替换多发生在密码子的第三位点。盘丽鱼与其它3种盘丽鱼属鱼类的遗传距离在0.005～0.01之间,而绿盘丽鱼、褐盘丽鱼和蓝盘丽鱼彼此间的遗传距离在0.012～0.014之间,由此推测盘丽鱼似还没有分化到种的水平;本文还在绿盘丽鱼、褐盘丽鱼、蓝盘丽鱼和盘丽鱼4种盘丽鱼属鱼类的cytb基因比较分析的基础上构建了系统进化树。

Genetic relationship of Symphysodon based on mitochondrial cytochrome b gene sequence

Mitochondrial cytochrome b(cytb) gene complete sequences of Symphysodon aequifasciata aequifasciata,S. a. axelrodi and S. discus were amplified with PCR technique and sequenced. By comparing with the same gene sequence of S. a. haraldi recorded in the GenBank,the sequences of 1137 bp DNA had 23 nucleotide sites substituted (2.02%),among of them 22 base substitutions were transition and only one was transversion,most of the base substitution happened in the third locus of the codon. The genetic distance of the cytb gene sequence was ~0.005 -0.01 between S. discus and the other three S. aequifasciata,and 0.012-0.014 among S. a. aequifasciata、S. a. axelrodi and S. a. haraldi,which indicated that S. discus perhaps did not evolve to the level of species. Phylogenetic trees were constructed with neighbor-joining method and unweighted pair group method using arithmetic average method.