Abstract Nematocera (lower Diptera) is a taxonomically diverse group with ~52 000 species in 40 families, including many important agricultural and sanitary pests. The number and composition of nematoceran infraorders have long been subject to debate. The use of mitochondrial genomes for resolving these questions shows considerable promise. Herein, we sequenced and annotated the complete or nearly complete mitochondrial genomes of eight nematoceran species from seven families, representing the first mitochondrial genomes of two infraorders and six families. They range in size from 14 447 to 16 255 bp and all contain 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and an AT-rich region. Like other nematocerans, the arrangement of genes of their mitochondrial genomes is identical to the presumed ancestral arrangement. A phylogenetic analysis was conducted by using mitochondrial genomes of 116 representatives from Diptera, Mecoptera and Siphonaptera. Our phylogenetic results support both new and traditional arrangements. The small, highly specialized family Deuterophlebiidae appears to be sister to all remaining Diptera, while Nymphomyiidae and Blephariceridae are nested within Culicomorpha and Psychodomorpha, respectively; hence, the recognition of ‘Blephariceromorpha’ as a valid monophyletic infraorder is discouraged. Anisopodidae is supported as the sister group of Brachycera.

中文翻译：

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线虫（下双翅目）线粒体基因组的新数据：特征、结构和系统发育意义

摘要 线虫目（下双翅目）是一个分类学多样化的群体，有 40 科约 52 000 种，包括许多重要的农业和卫生害虫。线虫亚目的数量和组成长期以来一直存在争议。使用线粒体基因组来解决这些问题显示出相当大的前景。在这里，我们对来自 7 个科的 8 个线虫物种的完整或几乎完整的线粒体基因组进行了测序和注释，代表了两个亚目和六个科的第一个线粒体基因组。它们的大小范围从 14 447 到 16 255 bp，都包含 13 个蛋白质编码基因、两个核糖体 RNA 基因、22 个转移 RNA 基因和一个富含 AT 的区域。和其他线虫一样，他们线粒体基因组的基因排列与推测的祖先排列相同。通过使用来自双翅目、长翅目和虹翅目的 116 个代表的线粒体基因组进行系统发育分析。我们的系统发育结果支持新的和传统的安排。小型的、高度专业化的 Deuterophlebiidae 似乎是所有剩余双翅目的姐妹，而 Nymphomyiidae 和 Blephariceridae 分别嵌套在 Culicomorpha 和 Psychodomorpha 中；因此，不鼓励将“Blephariceromorpha”识别为有效的单系亚目。Anisopodidae 被支持为 Brachycera 的姐妹群。我们的系统发育结果支持新的和传统的安排。小型的、高度专业化的 Deuterophlebiidae 似乎是所有剩余双翅目的姐妹，而 Nymphomyiidae 和 Blephariceridae 分别嵌套在 Culicomorpha 和 Psychodomorpha 中；因此，不鼓励将“Blephariceromorpha”识别为有效的单系亚目。Anisopodidae 被支持为 Brachycera 的姐妹群。我们的系统发育结果支持新的和传统的安排。小型的、高度专业化的 Deuterophlebiidae 似乎是所有剩余双翅目的姐妹，而 Nymphomyiidae 和 Blephariceridae 分别嵌套在 Culicomorpha 和 Psychodomorpha 中；因此，不鼓励将“Blephariceromorpha”识别为有效的单系亚目。Anisopodidae 被支持为 Brachycera 的姐妹群。