蝗科高级阶元的分子系统发育(英文）

迄今,蝗科内各分类阶元之间的系统发生关系大部分是未知的。本文用来自中国24种蝗科昆虫的12SrDNA和16SrDNA2个基因的联合序列(共795bp)数据,以锥头蝗科的锥头蝗(Pyrgomorpha conica)为外群,重建了分子系统树。研究结果表明,在12SrDNA与16SrDNA组成的联合数据中,转换的替代速率明显比颠换的替代速率高得多,核酸的替代已经发生了饱和。分子系统树表明:斑翅蝗亚科是一单系群,该亚科是一个合法的亚科,但斑腿蝗亚科和蝗亚科都不是单系群;斑翅蝗亚科在蝗科内是一个相对原始的类群,而稻蝗亚科比斑翅蝗亚科相对进化,比蝗科的其他亚科的种类相对原始。     

基于Cyt b基因的网翅蝗科系统发生重建

研究测定了蝗总科25种蝗虫的线粒体Cyt b部分序列,并从GenBank中下载了19种蝗亚目昆虫的Cyt b基因相应序列片段。本文目的是要建立网翅蝗科的系统发育关系并说明网翅蝗科在蝗总科中的分类地位。以瘤锥蝗科的云南蝗Yunnanites coriacea和长额橄蝗Tagasta marginella作为外群,用MP法和贝叶斯法重建系统发生树。比对后的序列长度是384 bp,包括167个简约信息位点。A T平均含量为70.7%,C G 平均含量29.3%。分子系统树表明:网翅蝗科并不是一个单系群。网翅蝗亚科和竹蝗亚科并非单系群。现存的雏蝗属并非单系群,应该是多系群。分子系统学研究结果和传统的基于形态特征的网翅蝗科分类体系有很大的不同。     

基于线粒体Cyt b,16S rDNA和核28S rDNA的中国斑腿蝗科(直翅目,蝗总科)九亚科间的系统发育关系研究

基于线粒体Cytb、16S rDNA和核28S rDNA的部分序列的联合数据集,重建了中国斑腿蝗科9亚科26种蝗虫和癞蝗科笨蝗(外群)间的系统发育关系。结果显示:1)除黑蝗亚科、秃蝗亚科和切翅蝗亚科外,其余6亚科的单系性都得到支持;2)黑蝗亚科似乎应当与秃蝗亚科合并为一个亚科,且与其他几个亚科亲缘关系相对较远;3)凸额蝗属应该由切翅蝗亚科中独立出来;4)卵翅蝗亚科和稻蝗亚科是姐妹群;5)星翅蝗亚科、黑背蝗亚科、斑腿蝗亚科、刺胸蝗亚科及切翅蝗亚科中的凸额蝗属间的关系较近。     

基于COⅡ基因序列的斑腿蝗科部分亚科的分子系统学研究

采用PCR产物直接测序法测定了斑腿蝗科10个亚科16属22种的COⅡ基因585 bp的片段, 对序列的碱基组成进行了分析,并评估了数据集的系统发育信号;最后,以癞蝗科的肃南 短鼻蝗作为外群,采用NJ法、MP法、ML法以及贝叶斯推论法构建了系统树,以解决这些物种所代表的亚科之间的系统发育关系。结果表明：22种斑腿蝗科昆虫的COⅡ基因序列碱基组成表现强烈的A+T含量偏向性。对COⅡ基因585 bp序列片段构成的全数据组和根据密码子不同位点划分的密码子第一、第二和第三位点数据组的系统发育信号分析显示,所有数据组都具有一定的系统发育信息。在4种方法得到的合一树中发现： （1）星翅蝗亚科、刺胸蝗亚科、黑背蝗亚科、斑腿蝗亚科的亲缘关系较近;（2）卵翅蝗亚科与稻蝗亚科亲缘关系较近,建议卵翅蝗亚科似乎应归入稻蝗亚科中,板胸蝗亚科与这两个亚科的关系较近;（3）黑蝗亚科和秃蝗亚科似乎应合并为一个亚科;（4）切翅蝗亚科的4个属未聚在一起,表明这些属的区别较大,不是一个单系群;（5）黑蝗亚科和秃蝗亚科关系较近,且与本研究中其他几个亚科的亲缘关系相对较远。研究结果表明COⅡ基因在解决斑腿蝗科的亚科以下属种间的系统发育关系时是一个有效的分子标记。     

基于16S rDNA序列探讨中国剑角蝗科的单系性及其六属的系统发育关系

在中国学者夏凯龄的分类系统中,剑角蝗科Acrididae一直被看作是单系群,包含6个亚科。但是,近年来的研究对其单系性争议较大。为探讨其单系性和剑角蝗属等6属的系统发育关系,我们测定了剑角蝗科14种蝗虫的16S rRNA基因部分序列,并从GenBank中下载了1种蝗虫的同源序列。以蚱科的2个种作外群,用NJ、MP及ML法重建系统发生树。由三棵分子系统树中得出的系统发生关系与中国的分类系统差别较大,都不支持剑角蝗科是单系群,但与国外Kevan的系统相一致,提示我们国内的分类系统亟待修改和完善。长腹蝗亚科与斑腿蝗科的亲缘关系要近于与剑角蝗科的其他种类的关系。另外,尽管所测的红足剑角蝗和上海剑角蝗的16S rDNA的片段序列完全相同,我们仍不能断定二者是同一个物种[动物学报52 (2) : 302 -308 , 2006]。     

基于线粒体基因Cytb和COI的蝗科中五亚科分子系统发育关系分析（直翅目: 蝗总科）（英文）

本研究基于Cytb 基因和COI基因的部分序列来推断17种蝗虫之间的系统发育关系。这17种蝗虫均采自国内,代表了蝗科(Acrididae)5个亚科：黑蝗亚科(Melanoplinae)、斑腿蝗亚科(Catantopinae)、刺胸蝗亚科(Cyrtacanthacridinae)、斑翅蝗亚科(Oedipodinae)和大足蝗亚科(Gomphocerinae)。采用联合序列方法进行分析,结果显示：Cytb 和COI联合序列长度为1 998 bp,其中A和T总含量为72.13%,G和C总含量为27.87%。联合序列共包含了889个保守位点,1 109个变异位点,在这些变异位点中有838个简约信息位点。系统发生树采用邻接法（NJ）、最大简约法（MP）和最大似然法（ML）进行构建。使用蜢总科的变色乌蜢Erianthus versicolor 和 Erianthus sp. 两个种作为外群。结果表明：大足蝗亚科和斑腿蝗亚科的单系性没有得到支持。斑翅蝗亚科内部各种聚成一个大支,在本研究中该亚科的单系性得到支持,与前人的研究结论相同。大足蝗亚科、斑腿蝗亚科、刺胸蝗亚科和黑蝗亚科这4科关系非常近,可以考虑将其合并为一个亚科。同时,我们发现基于Cytb和COI基因联合序列推断蝗科内各亚科间的系统发生关系并不十分可靠。     

基于线粒体ND2基因的中国斑翅蝗科部分种类分子系统学研究（直翅目：蝗总科）

本文的目的是通过对斑翅蝗科部分种类的线粒体ND2基因进行分析,重建斑翅蝗科昆虫的系统发育关系,并探讨分子系统发育关系和传统分类结果的异同。扩增并测定了我国斑翅蝗科10属16种蝗虫的线粒体ND2全基因1 023 bp的序列,对序列的碱基组成、转换颠换、系统发育信号等进行了分析。并基于ND2全基因序列数据,分别采用邻接法（NJ）、最简约法（MP）、最大似然法（ML）和贝叶斯法重建了10属16种蝗虫的系统发育关系。结果表明：斑翅蝗科蝗虫ND2全基因A+T含量平均为74.6%;痂蝗亚科和异痂蝗亚科没能得到区分,建议合并为一个亚科;而斑翅蝗亚科和飞蝗亚科的分类地位还存在争议。     

基于18S rDNA的蝗总科分子系统发育关系研究及分类系统探讨

将自测的我国直翅目蝗总科7科7种和从GenBank中下载的17种直翅目昆虫的18S rDNA序列片段进行了同源性比较,用似然比检验的方法对序列比对结果进行了碱基替代模型的选择,以蚱总科的Paratettix cucullatus和蜢总科的Stiphra robusta作外群,用NJ、MP、ML和贝叶斯法构建了分子系统树。在获得的1 849 bp的序列中,有205个变异位点,74个简约信息位点; A、T、C和G的碱基平均含量分别为23.9%、24.3%、23.8%和28.0%,碱基组成基本上无偏异。分子系统树表明：所研究的内群聚为4支,锥头蝗科、瘤锥蝗科、斑腿蝗科、网翅蝗科、槌角蝗科和剑角蝗科都不是单系。建议将蝗总科分为4科,即锥头蝗科、大腹蝗科、癞蝗科和蝗科。     

蝗总科部分种类16S rDNA的分子系统发育关系

将自测的我国直翅目蝗总科8科8个种和从互联网GenBank中检索到相关物种的线粒体基因组：16S rDNA序列片段进行同源性比较,计算核苷酸使用频率,并构建分子系统树。在获得的480bp的序列中。A T约占70．7％,G C为29．3％,颠换取代(transversion)的速率大于或接近转换取代(transition)的速率,其中188个核苷酸位点存在变异。研究结果表明：在直翅目蝗总科有差异的188bp中,属内种间的碱基序列差异仅为1．5％,科内属间为3．5％～3．6％,科间差异为4．8％～15．8％,亚目间差异达到15．2％～25．6％。分子系统树表明：科内的属和属内的种均优先聚在一起;蝗总科8科的起源关系为：锥头蝗科→瘤锥蝗科→癞蝗科→斑翅蝗科→剑角蝗科→网翅蝗科和槌角蝗科→斑腿蝗科;锥头蝗科与瘤锥蝗科关系较近,是蝗总科内最原始的类群;槌角蝗科和网翅蝗科互为姐妹群,与最进化的斑腿蝗科关系较近;蚤蝼科为独立的一支,最先分出,似为一个亚目,与现用的分类系统有明显差别;哈螽科(螽嘶总科)和蟋蟀科聚在一起为剑瓣亚目(Ensifera),蚱科和蝗总科的8科组成短瓣亚目(Caehfera),同现用的分类系统。     

斑腿蝗科精小管形态及其分类学意义探讨

首次对斑腿蝗科 3 5属 4 6种的精小管形态进行了度量描记 ,并应用SPSS软件对上述种类的精小管量度作了统计分析。结果表明 ,斑腿蝗科精小管形态在属内种间具有稳定性 ,在亚科级阶元具有其各自的特征 ,可作为亚科间比较的一项有用指标。其中 ,稻蝗亚科精小管较短小 ,接近于蚱总科及蝗总科癞蝗科等原始类群 ,显示其原始性 ;板胸蝗亚科较为进化并与秃蝗、裸蝗亚科具较近亲缘关系。斑腿蝗亚科各属间精小管形态变异较大 ,但以梭形至杆状为主 ,显示其较进化的特点。本文结果初步表明 :作为一个方面的分类学性状 ,蝗虫精小管形态可以作为属上高级阶元的比较特征。     

线蛱蝶亚科蝶类部分类群线粒体COI基因的分子系统发生分析

以线粒体细胞色素氧化酶I（COI）基因作分子标记,对线蛱蝶亚科蝴蝶进行序列测定．序列分析的结果表明．经比对和处理后的序列总长度是645bp,其中有199个变异位点,147个简约信息位点;所编码的氨基酸序列中有18个变异位点,7个信息位点．A＋T平均含量为69．6％,G＋C平均含量为30．4％,碱基组成出现AT偏斜．以蛱蝶亚科及秀蛱蝶亚科物种为外类群,用NJ、MP及贝叶斯法重建了该亚科的系统发生树,探讨了它们主要类群间的系统发生关系．分子系统树显示,线蛱蝶亚科由以下3大支系：环蛱蝶族＋翠蛱蝶族、线蛱蝶族、丽蛱蝶族构成;其中,环蛱蝶族为单系群（NJ树也支持线蛱蝶族的单系性）;翠蛱蝶族与环蛱蝶族亲缘关系较近：丽蛱蝶族可能是该亚科较早分化出的一支．     

Phylogenetic reassessment of the Teloschistaceae (lichen-forming Ascomycota, Lecanoromycetes)

The Teloschistaceae is a widespread family with considerable morphological and ecological heterogeneity across genera and species groups. In order to provide a comprehensive molecular phylogeny for this family, phylogenetic analyses were carried out on sequences from the nuclear ribosomal ITS region obtained from 114 individuals that represent virtually all main lineages of Teloschistaceae. Our study confirmed the polyphyly of Caloplaca, Fulgensia and Xanthoria, and revealed that Teloschistes is probably non-monophyletic. We also confirm here that species traditionally included in Caloplaca subgenus Gasparrinia do not form a monophyletic entity. Caloplaca aurantia, C. carphinea and C. saxicola s. str. groups were recovered as monophyletic. The subgenera Caloplaca and Pyrenodesmia were also polyphyletic. In the subgenus Caloplaca, the traditionally recognized C. cerina group was recovered as monophyletic. Because this study is based solely on ITS, to maximize taxon sampling, the inclusion of phylogenetic signal from ambiguously aligned regions in MP (recoded INAASE and arc characters) resulted in the most highly supported phylogenetic reconstruction, compared with Bayesian inference restricted to alignable sites.     

Quantification of homoplasy for nucleotide transitions and transversions and a reexamination of assumptions in weighted phylogenetic analysis

Nucleotide transitions are frequently down-weighted relative to transversions in phylogenetic analysis. This is based on the assumption that transitions, by virtue of their greater evolutionary rate, exhibit relatively more homoplasy and are therefore less reliable phylogenetic characters. Relative amounts of homoplastic and consistent transition and transversion changes in mitochondrial protein coding genes were determined from character-state reconstructions on a highly corroborated phylogeny of mammals. We found that although homoplasy was related to evolutionary rates and was greater for transitions, the absolute number of consistent transitions greatly exceeded the number of consistent transversions. Consequently, transitions provided substantially more useful phylogenetic information than transversions. These results suggest that down-weighting transitions may be unwarranted in many cases. This conclusion was supported by the fact that a range of transition: transversion weighting schemes applied to various mitochondrial genes and genomic partitions rarely provided improvement in phylogenetic estimates relative to equal weighting, and in some cases weighting transitions more heavily than transversions was most effective.     

A preliminary study on relationships among selected Australian members of the tribe Spilomelini (Lepidoptera: Crambidae: Pyraustinae)

A preliminary study was conducted on phylogenetic relationships among some selected genera of the Australian Spilomelini, focusing on relationships among the Australian Glyphodes group (Glyphodes Guenée, 1854, Dysallacta Lederer, 1863, Talanga Moore, 1885 and Agrioglypta Meyrick, 1932) and the 17 genera which are morphologically similar to it. Representatives of three genera of the Pyarustini were used as outgroups. Cladistic analysis of morphological data from the adult moths produced 10 equally MP trees (length = 221, CI=0.294, and RI=0.608). The clade formed by the 21 selected genera of the Australian Spilomelini had low bootstrap support even though a good apomorphy supported the monophyly of this group, namely, a strong, bilobed praecinctorium of abdominal tympanal organs. The analysis showed that the Glyphodes group is not monophyletic because the genus Chrysothyridia Snellen appears within it in the 10 MP trees. The concept of the Glyphodes group should be expanded to include Chrysothyridia and also the Synclera Zeller and Didymostoma (Walker) since the Synclera + Didymostoma clade, as the hypothesised sister group of the Glyphodes group, is not sufficiently supported as a separate monophyletic group. The analysis also showed that genus Glyphodes is not a monophyletic group, while Metallarcha Meyrick is a monophyletic group.     

Phylogeny of ips DeGeer species (Coleoptera: scolytidae) inferred from mitochondrial cytochrome oxidase I DNA sequence

We used 766 bp of DNA sequence data from the mitochondrial cytochrome oxidase I gene to reconstruct a phylogeny for 39 of 43 Ips species, many of which are economically important bark beetles. The phylogeny was reconstructed using equally weighted and weighted parsimony. In both analyses, peripheral clades were well supported while internal clades were poorly supported. Phylogenetic analysis of translated amino acids produced a poorly resolved tree that was discordant with trees reconstructed with nucleotide sequence data. Two main conclusions are drawn about the monophyly of Ips and traditional systematic groups within Ips. First, Ips is monophyletic only when I. mannsfeldi, I. nobilis, and the concinnus and latidens species groups are excluded. The latidens group, I. mannsfeldi, and I. nobilis form a monophyletic group with 3 Orthotomicus species, while the concinnus group has a more basal position. Second, the majority of the species groups in the current classification for Ips are not monophyletic. European Ips species do not form a monophyletic group, contrary to common usage, and are dispersed on the phylogenetic tree among North American species. These results indicate that a formal systematic revision of Ips is needed.