18s rDNA Sequences and the Holometabolous Insects
18s rDNA Sequences and the Holometabolous Insects
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DOI：
10.1016/1055-7903(92)90002-x
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发表时间：
1992-12-01
影响因子：
4.1
通讯作者：
Berbee, Mary L.
中科院分区：
文献类型：
--
作者：
Carmean, David;Kimsey, Lynn S.;Berbee, Mary L.
全变态昆虫（具有完全变态的昆虫：甲虫、黄蜂、苍蝇、跳蚤、蝴蝶、草蛉等）是一个单系群体，包括世界上大多数动物物种。全变异目通过形态特征得到了很好的定义，但各目之间的关系尚不清楚。为了寻找能够阐明昆虫间相互关系的DNA区域，我们对膜翅目（锯蝇和黄蜂）、神经翅目（草蛉和蚁蛉）、管翅目（跳蚤）和甲翅目（蝎子）等14个昆虫科的代表进行了18s核糖体RNA基因5'端约1080个核苷酸的测序。我们将这些序列与已发表的鞘翅目（甲虫）和双翅目（蚊子和果蝇）的昆虫序列以及蚜虫、虾和蜘蛛的外群进行了比对。与本研究中检查的其他昆虫不同，神经翼目动物有丰富的A-T插入或扩张区域：蚁群中的一个类似于260 bp长。双翅目18s rDNA进化迅速，在排列序列中有超过3倍的替换，不对齐的核苷酸比其他全代谢动物多2-3倍，这违反了昆虫的分子钟。当我们从分析中排除长分支分类群（双翅目、虾类和蜘蛛）时，最简约（最小长度）的树将甲虫置于其他全变异目的基础上，并支持包括跳蚤和蝎子在内的形态学单系分支（96%的bootstrap支持）。然而，大多数间序关系在极大似然或自举测试中没有得到显著支持，并且对分析所包含的分类群敏感。最简约树和最大似然树都将鞘翅目和神经翅目区分开来，但这种区分没有统计学意义。膜翅目昆虫相对于其他目的位置尚未明确。在分析中加入较少派生的成员使膜翅目出现泛蜂性。神经翅目的两个代表组合在一起，两个双翅目也是如此，两对都有非常重要的引导支持。1892学术出版社，Inc.
The Holometabola (insects with complete metamorphosis: beetles, wasps, flies, fleas, butterflies, lacewings, and others) is a monophyletic group that includes the majority of the world's animal species. Holometabolous orders are well defined by morphological characters, but relationships among orders are unclear. In a search for a region of DNA that will clarify the interordinal relationships we sequenced approximately 1080 nucleotides of the 5' end of the 18s ribosomal RNA gene from representatives of 14 families of insects in the orders Hymenoptera (sawflies and wasps), Neuroptera (lacewing and antlion), Siphonaptera (flea), and Mecoptera (scorpionily). We aligned the sequences with the published sequences of insects from the orders Coleoptera (beetle) and Diptera (mosquito and Drosophila), and the outgroups aphid, shrimp, and spider. Unlike the other insects examined in this study, the neuropterans have A-T rich insertions or expansion regions: one in the antlion was similar to 260 bp long. The dipteran 18s rDNA evolved rapidly, with over 3 times as many substitutions among the aligned sequences, and 2-3 times more unalignable nucleotides than other Holometabola, in violation of an insect-wide molecular clock. When we excluded the long-branched taxa (Diptera, shrimp, and spider) from the analysis, the most parsimonious (minimum-length) trees placed the beetle basal to other holometabolous orders, and supported a morphologically monophyletic clade including the fleas + scorpionflies (96% bootstrap support). However, most interordinal relationships were not significantly supported when tested by maximum likelihood or bootstrapping and were sensitive to the taxa included in the analysis. The most parsimonious and maximum-likelihood trees both separated the Coleoptera and Neuroptera, but this separation was not statistically significant. The position of the Hymenoptera relative to other orders was not clarified. Including the less derived members in the analysis made the Hymenoptera appear paraphyletic. The two representatives of Neuroptera grouped together as did the two Diptera, both pairs with very significant bootstrap support. (C) 1892 Academic Press, Inc.