Caccone A, Garcia B A, Powell J R
Department of Biology, Yale University, New Haven, Connecticut, 06520-8104, USA.
Insect Mol Biol. 1996 Feb;5(1):51-9. doi: 10.1111/j.1365-2583.1996.tb00040.x.
We have sequenced the AT-rich control region of the mitochondrial DNA (mtDNA) of six species in the Afrotropical Anopheles gambiae complex and the closely related A. christyi. Contrary to expectations, the AT-rich region in this group is evolving rather slowly, more slowly than the third position of mtDNA protein-coding genes. Despite being relatively conserved between species, we detected intraspecific and intra-individual (heteroplasmy) variation in this region. Phylogenetically, we found we could place the rare endemic A. bwambae as a sister taxon to A. melas, the same evolutionary position as indicated by chromosomal inversions. The outgroup, A. christyi, gave evidence of the root of the tree. In comparing the molecular trees with that deduced by chromosomal inversions, they are completely congruent with the exception of the placement of A. arabiensis. The anomalous position of this species can be explained by introgression with A. gambiae. From the phylogenetic position, we could infer mtDNA gene flow from A. gambiae to A. arabiensis.
我们已对非洲疟蚊复合体中六个物种以及与之密切相关的克里斯蒂按蚊的线粒体DNA（mtDNA）富含AT的控制区进行了测序。与预期相反，该类群中的富含AT区域进化相当缓慢，比mtDNA蛋白质编码基因的第三位进化得更慢。尽管该区域在物种间相对保守，但我们在该区域检测到了种内和个体内（异质性）变异。在系统发育方面，我们发现可以将罕见的地方性物种布氏按蚊置于梅拉斯按蚊的姐妹分类单元位置，这与染色体倒位所表明的进化位置相同。外类群克里斯蒂按蚊给出了树的根部证据。在将分子树与由染色体倒位推导的树进行比较时，除了阿拉伯按蚊的位置外，它们完全一致。该物种的异常位置可以通过与冈比亚按蚊的基因渗入来解释。从系统发育位置来看，我们可以推断线粒体DNA从冈比亚按蚊流向阿拉伯按蚊。
