山稻蝗及相关物种Cyt b基因序列及其遗传关系

中国7个不同地理区域的山稻蝗Oxya agavisa共16个个体的线粒体DNA细胞色素b基因中间部分序列被测定，分析和比较，同时与小稻蝗O.inricata，日本稻蝗O.japonica和中华稻蝗O.chinensis相应序列进行比较，用瘤锥蝗科的曲尾似橄蝗Pseudomorphacris hollisi和蚱科的日本蚱Tetrix japonica作外群，构建了山稻蝗不同单倍型及其相关物种的NJ分子系统树。在获得的山稻蝗432bp的序列中，A＋T约占71．0％，其中9个核苷酸位点存在变异（约占所测核苷酸的2．08％），但权有1个位点引起了氨基酸的变异，就每个氨基酸密码子来看，第三位点的A＋T含量较，达88．3％。分子系统树显示，山稻蝗6个单倍型聚为一个簇，彼此之间有一定的分歧，其分枝与地理分布没有直接的关系；该种与日本稻蝗关系较近，与中华稻蝗和小稻蝗相对较远。并对此进行了讨论。

Genetic Relationships among Oxya agavisa and Other Relative Species Revealed by Cyt b Sequences

The mtDNA Cyt b genes (432bp) were sequenced for 16 individuals of Oxya agavisa from 7 Chinese region, 3 other relative species ( O japonica, O chinensis and O intricata ), and two outgroup species ( Pseudomorphacris hollisi and Tetrix japonica ) In the obtained sequences of O agavisa , A%+T%was about 71 0% and 9 polymorphic nucleotide sites were observed (about 2 08%), among which no transversions were observed and only one substitution resulted in the variation of amino acid In the case of 3 other species of Oxya , A% +T% was about 72 5%( O chinensis ) and 70%( O japonica and O intricata ), respectively A%+T% in the third site was much higher than the other two sites in all the analyzed Oxya species ( O agavisa , 88 3%; O chinensis , 92 4%; O japonica , 86 8%; O intricata , 89 5% ) Six haplotypes of O agavisa were compared with the 3 other Oxya species and 73 polymorphic nucleotide sites were examined (about 16 9%) in all Phylogenetic tree was constructed with the Neighbor Joining methods using P hollisi and T japonica as outgroups and the confidence of nodes in the tree was evaluated by Bootstrap(1000 replicates) The NJ tree showed that different haplotypes of O agavisa clustered together,but no clear relationships between haplotypes and the geographic regions would be inferred The population from Mount Wuyi belongs to the peculiar group and is relatively distant to other populations In addition,the NJ tree showed that O agavisa was closer to O japonica and O chinensis closer to O intricata , which was different from the previous results of morphologic, chromosome karyotype and bands The relationships among different species of Oxya still need to be further clarified