The complete mitochondrial genome of Diadegma semiclausum (Hymenoptera: Ichneumonidae) indicates extensive independent evolutionary events
The complete mitochondrial genome of Diadegma semiclausum (Hymenoptera: Ichneumonidae) indicates extensive independent evolutionary events
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Diadegma semiclausum（膜翅目：姬蜂科）的完整线粒体基因组表明了广泛的独立进化事件
DOI：
10.1139/g09-008
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发表时间：
2009-04-01
期刊：
影响因子：
3.1
通讯作者：
Chen, Xue-xin
中科院分区：
文献类型：
--
作者：
Wei, Shu-jun;Shi, Min;Chen, Xue-xin
很少有完整的线粒体基因组代表有限的家庭在Hypletera的顺序已经测序。本研究对半闭弯尾姬蜂Diadegma semiclausum（Hyplittera：Ichandionidae）的线粒体基因组进行了全序列测定。该基因组全长18728 bp，是全序列中第二大的六足类线粒体基因组，A+T含量最高，为87.4%。与祖先的排列相比，四种tRNA发生了重排。基因重排机制在所有三个重排区域中是不同的。六个tRNA有一个大的可变环，这是没有发现在其他后生动物线粒体基因组。trnS（（AGY））使用异常反密码子TCT，而trnK使用正常CTT。富含A+ T的区域很长（2161 bp）。在cox 1和cox 2之间有一个1515 bp的串联重复区，其中A+ T含量极高（99.1%），有3种重复元件，最可能的祖先元件来自cox 1的3'端。独立的串联重复后突变-插入-缺失是解释该区域形成的最佳模型。这些结果表明，独立的进化事件发生广泛，如基因重排事件，基因重排机制，衍生的tRNA可变环，和串联重复区的进化过程，所有这些可能有助于在Hypherteran线粒体基因组的多样性特征。
Few complete mitochondrial genomes representing limited families in the order Hymenoptera have been sequenced. Here, we sequenced the complete mitochondrial genome of Diadegma semiclausum (Hymenoptera: Ichneumonidae). This genome is 18 728 bp long, the second largest hexapod mitochondrial genome sequenced in its entirety and that with the highest A+T content at 87.4%. Four tRNAs are rearranged compared with the ancestral arrangement. Gene rearrangement mechanisms are different among all three rearranged regions. Six tRNAs have a large variable loop, which is not found in other metazoan mitochondrial genomes. trnS((AGY)) uses the abnormal anticodon TCT but trnK uses the normal CTT. The A+T-rich region is very long (2161 bp). An extremely A+T-rich (99.1%) 1515 bp tandem repeat region with three types of repeat elements is located between cox1 and cox2, and the most likely ancestral element originated from the 3' end of cox1. Independent tandem duplications followed by mutation-insertion-deletion is the best model to explain the formation of this region. These results indicate that independent evolutionary events occurred extensively, such as gene rearrangement events, gene rearrangement mechanisms, derivation of tRNA variable loops, and tandem repeat region evolutionary processes, all of which likely contribute to the diversified features of hymenopteran mitochondrial genomes.