以ND4L和ND4基因为标记探讨黑腹果蝇种组的系统发育关系

多年来的形态学、染色体组学以及DNA序列几个方面的研究均没有很好地阐明黑腹果蝇种组内的系统发育关系。本实验测定了33个样品的ND4和31个样品的ND4L基因序列，以D．obscuroides为外群，用最大简约法和Bayesian法分别构建进化树。结果表明两种方法构建的拓扑结构一致，而且大部分支系的支持率较高。整个黑腹果蝇种组分成三大谱系：1）montium种亚组；2）ananssae种亚组；3）Oriental种亚组（melanogaster、ficsphila、eugracilis、elegans、suzukii、takahashii）。montium是最早分化的种亚组。在第三谱系中，melanogaster分化得最早；然后依次是ficsphila，eugracilis，elegans；suzukii与takahashii为姐妹种亚组，最后分化。

Phylogeny of melanogaster Species Group Inferred from ND4L and ND4 Genes

The relationships within Drosophila melanogaster species group are controversial from morphology, chromosomes and DNA sequences. This study utilises a molecular approach aimed at uncovering the phylogenetic relationships among 33 taxa representing 8 subgroups of D. melanogaster species groups. Mitocondrial ND4L-ND4 was sequenced in the all 8 subgroups covering a wide geographic area. MP and Bayesian analysis produced an identical tree topology with relatively strong support in most nodes. It reveals that the melanogaster species group clustered in three main lineages: 1) montium subgroup; 2) ananassae subgroup; 3) Oriental subgroups (melanogaster, ficsphila, eugracilis, elegans, suzukii and takahashii). The montium subgroup branched off first, followed by the ananassae subgroup. In the third lineage, melanogaster is the most divergent subgroup followed by ficsphila, eugracilis, elegans in that order. The suzukii and takahashii sister subgroups are the last to branch off.