Mitochondria1 cytochromeb sequences variation of Protura and molecular systematics of Apterygota

Mitochondrial cytochromeb genes of about 450 bp fragments from 3 proturan species, 5 collembolan species and 2 dipluran species have been sequenced. The number of nucleotide substitutions and Kimura 2-parameter distances have also been calculated, and a series of molecular phylogenetic trees reconstructed by using parsimony and distance methods. The proturan, collembolan and dipluran species have evolved monophyletic groups. The results suggest that Protura and Collembola are sister groups, while Diplura is more or less demonstrating a closer phylogenetic relationship to the pterygotan insects. The phylogeny and their systematic position of protura and other groups are also discussed.     

Mitochondrial cytochrome b sequences variation of Protura and molecular systematics of Apterygota

Mitochondrial cytochrome b genes of about 450 bp fragments from 3 proturan species, 5 collembolan species and 2 dipluran species have been sequenced. The number of nucleotide substitutions and Kimura 2-parameter distances have also been calculated, and a series of molecular phylogenetic trees reconstructed by using parsimony and distance methods. The proturan, collembolan and dipluran species have evolved monophyletic groups. The results suggest that Protura and Collembola are sister groups, while Diplura is more or less demonstrating a closer phylogenetic relationship to the pterygotan insects. The phylogeny and their systematic position of protura and other groups are also discussed.     

基于Cyt b基因全序列分析河南7种菊头蝠系统发育关系

采用分子系统发育分析方法对菊头蝠科蝙蝠的系统发育关系和分类地位进行研究,以7种127个蝙蝠为研究对象,测定了mtDNA Cytb基因全序列(1140kb),用最大简约法(maximum parsimony,MP)和最大似然法(maximum likelihood,ML)建系统发育树,对菊头蝠种间亲缘关系及分类地位进行分析,角菊头蝠、菲菊头蝠和大耳菊头蝠属于较原始的种类,且彼此间有较近的亲缘关系;大菊头蝠、皮氏菊头蝠关系较近,为较原始的类群;马铁和中菊头蝠关系较近,为后分化的类群.     

Mitochondrial protein phylogeny joins myriapods with chelicerates

The animal phylum Arthropoda is very useful for the study of body plan evolution given its abundance of morphologically diverse species and our profound understanding of Drosophila development. However, there is a lack of consistently resolved phylogenetic relationships between the four extant arthropod subphyla, Hexapoda, Myriapoda, Chelicerata and Crustacea. Recent molecular studies have strongly supported a sister group relationship between Hexapoda and Crustacea, but have not resolved the phylogenetic position of Chelicerata and Myriapoda. Here we sequence the mitochondrial genome of the centipede species Lithobius forficatus and investigate its phylogenetic information content. Molecular phylogenetic analysis of conserved regions from the arthropod mitochondrial proteome yields highly resolved and congruent trees. We also find that a sister group relationship between Myriapoda and Chelicerata is strongly supported. We propose a model to explain the apparently parallel evolution of similar head morphologies in insects and myriapods.     

Asian origin for Polystichum （Dryopteridaceae） based on rbcL sequences

Chloroplast rbcL sequences of 60 species of Polystichum sensu lato (s.l.), including 23 new sequences from southwest China, were used to assess the phylogenetic relationships within the genus. On the basis of estimated evolution rate of rbcL gene and the genetic distance data that passed relative-rate tests, we further estimated the divergence times between some clades of the genus. The phylogenetic relationships were inferred using the neighbor-joining and maximum-parsimony methods, both methods producing trees with completely congruent topology. These trees reveal that all species of Polystichum s.l. in this study (including Cyrtomium and Cyrtomidictyum) form a monophyletic group. The basal split in Polystichum s.l. separates a clade with all Asian members from a clade containing other species from all over the world. The phylogenetic and divergence time estimation results lead us to suggest that Polystichum s.l. originated in Asia in the late Late Cretacous (≈76 Ma) and migrated into other places in the world in early Eocene(≈46 Ma).     

Phylogeny and divergence of Chinese Angiopteridaceae based on chloroplast DNA sequence data （rbcL and trnL-F）

Marattioid ferns are an ancient lineage of primitive vascular plants that first appeared in the middle Carboniferous. Extant members are almost exclusively restricted to tropical regions, and the spe- cies-rich family Angiopteridaceae are limited in their distribution to the eastern hemisphere; relation- ships within the group are currently vague. Here the phylogenetic relationship between Angiopteris Hoffm. and Archangiopteris Christ et Gies. was evaluated based on the sequence analysis of chloro- plast rbcL gene and trnL-F intergenic spacer with MEGA2 and MrBayes v3.0b4. On the basis of the phy- logenetic pattern and fossil record, we further estimated the divergence time for the two genera. The phy- logenetic trees revealed that all species of Angiopteris and Archangiopteris in this study formed a monophyletic group with strong statistical support, but the relationship between the two genera re- mained unresolved based on individual sequence analysis. On the other hand, the sequence analyses of combined data set revealed that Archangiopteris species diverged first, indicating that Archangiop- teris may not be a direct derivative as traditionally assumed. The clade of Angiopteris and Archan- giopteris appears to have diversified in the late Oligocene (≈26 Ma) based on the molecular estimate. Thus, the evolutionary history of extant Angiopteris and Archangiopteris has been characterized by ancient origin and recent diversification, and these groups are not relic and endangered lineages as traditionally considered.     

New light shed on the oldest insect

Insects are the most diverse lineage of all life in numbers of species, and ecologically they dominate terrestrial ecosystems. However, how and when this immense radiation of animals originated is unclear. Only a few fossils provide insight into the earliest stages of insect evolution, and among them are specimens in chert from Rhynie, Scotland's Old Red Sandstone (Pragian; about 396-407 million years ago), which is only slightly younger than formations harbouring the earliest terrestrial faunas. The most well-known animal from Rhynie is the springtail Rhyniella praecursor (Entognatha; Collembola), long considered to be the oldest hexapod. For true insects (Ectognatha), the oldest records are two apparent wingless insects from later in the Devonian period of North America. Here we show, however, that a fragmentary fossil from Rhynie, Rhyniognatha hirsti, is not only the earliest true insect but may be relatively derived within basal Ectognatha. In fact, Rhyniognatha has derived characters shared with winged insects, suggesting that the origin of wings may have been earlier than previously believed. Regardless, Rhyniognatha indicates that insects originated in the Silurian period and were members of some of the earliest terrestrial faunas.     

基于线粒体细胞色素氧化酶Ⅰ亚基(COI)基因的两种枝吻纽虫系统发育关系分析

为了探讨纽虫之间的遗传差异及亲缘关系,对取自北海和湛江的中华枝吻纽虫(Dendrorhynchus sinensis)26个样本和湛江枝吻纽虫(Dendrorhynchus zhanjiangensis)3个样本的线粒体细胞色素氧化酶Ⅰ亚基(COI)基因部分片段进行序列测定,并结合从GenBank下载的其它纽虫序列,分析它们之间的系统发育关系。结果显示,中华枝吻纽虫26个个体共检测17个单倍型,湛江枝吻纽虫3个个体共检测到2个单倍型,其长度均为615bp;枝吻纽虫个体核苷酸序列A、T、G、C的含量相近,碱基组成均表现出A+T含量偏倚,即A+T含量明显高于G+C含量。中华枝吻纽虫的17个单倍型以及湛江枝吻纽虫的2个单倍型之间的遗传距离分别为0.002~0.013和0.008;而两种枝吻纽虫COI基因序列的遗传差异很大,彼此之间的遗传距离都在0.194以上,加之分子系统树(NJ)的拓扑结构也显示,作为同属的两种枝吻纽虫没有聚成1支,而是各自成支,这些表像都支持两种枝吻纽虫分别为独立有效物种的观点。中华枝吻纽虫的17个单倍型聚为1支后,与Cerebratulus marginatus,C.lacteus聚为1大支,而湛江枝吻纽虫的2个单倍型聚为1支后,与Lineus ruber和L.longissimus聚为1大支,表明枝吻纽虫属(Dendrorhynchus)并非单系。     

Whole-genome based Archaea phylogeny and taxonomy: A composition vector approach

The newly proposed alignment-free and parameter-free composition vector (CVtree) method has been successfully applied to infer phylogenetic relationship of viruses, chloroplasts, bacteria, and fungi from their whole-genome data. In this study we pay special attention to the phylogenetic positions of 56 Archaea genomes among which 7 species have not been listed either in Bergey’s Manual of Systematic Bacteriology or in Taxonomic Outline of Bacteria and Archaea (TOBA). By inspecting the stable monophyletic br...     

Phylogeny of fireflies (Coleoptera: Lampyridae) inferred from mitochondrial 16S ribosomal DNA，with references to morphological and ethological traits

We sequenced partial mitochondrial 16S ribosomal DNA (16S rDNA) of 18 firefly species from Southwest of China. Combined with homologous sequences previously reported, phylogenetic trees including Japanese, Korean and Chinese species were reconstructed by neighbor-joining, maximum parsimony and Bayesian methods. All reconstructions agree on most nodes of the trees. Monophyly of Lampyridae is not supported because Rhagophthalmus ohbai in Rhagophthalmidae is included within it. Lamprigera, a genus placed unreliably in Lampyrinae, shows a close relationship to Amydetinae. Monophyly of Luciolinae is not supported because Pristolycus sagulatus (Lampyrinae) is included within it. In the Luciolinae, monophyly of Curtos and Hotaria is well established, respectively, but both morphological and molecular data continue to indicate that Luciola is not monophyletic and its subdivision is indeed necessary. Within the Lampyrinae, both Pyrocoelia and Diaphanes are not monophyletic, but monophyly of Pyrocoelia+Diaphanes is well supported. Phylogeny of Diaphanes is discussed for the first time. Generic placement of a newly discovered species (Diaphanes pectinealis Li et Liang) sharing some characters of Pyrocoelia and Diaphanes challenges the delimitation of these two similar genera. With references to the firefly mating systems, we suggest that more emphases should be placed on those sexually selected characters such as antennal structure in taxonomy of Lampyridae.     

基于COI和D-Loop序列豫北虾虎鱼分子系统分析

虾虎鱼在河南省北部广泛分布,但其系统分类和多样性未有报道.从豫北原阳黄寺、安阳小南海、淇县淇河、长垣孙东闸、林州弓上水库等地采集虾虎鱼样本共计23尾,成都岷江样本6尾,分别扩增了线粒体COI基因和D-Loop序列.联合GenBank下载虾虎鱼的COI序列和D-Loop序列,构建了虾虎鱼的系统进化树.结果显示,采自黄寺、小南海、淇县、岷江地区的子陵吻虾虎鱼(Rhinogobius giurinus)聚为一个分支,而采自孙东闸和弓上水库的褐吻虾虎鱼(Rhinogobius brunneus)聚为一个单系群;这两种虾虎鱼遗传分化主要来自群体间.系统发育结果支持子陵吻虾虎鱼的韩国群体与中国群体构成姐妹群关系,中国不同地理种群间则相互交叉.     

基于18S rDNA序列研究腺介虫亚目系统发育关系

基于1 720 bp的18S rRNA基因序列以Darwinula sp.和Cytherelloidea. munechikai为外群,采用最大简约法（MP法）和邻接法（NJ法）对腺介虫亚目（Cypridocopina）3总科5科9种动物的系统发育关系进行了分析.结果表明：1） 现生腺介虫亚目动物为单系群;2） 两种营海水生活的介形类—海介虫总科（Pontocypridoidea）和大介虫总科（Macrocypridoidea）间的亲缘关系较近;3） 现生腺介虫总科（Cypridoidea）也为单系群,但该总科内各科间关系较复杂,主要分为两支,其中腺介虫科的Dolerocypris sp.与萤光介虫科的Candona holzkanpfi聚成一支;而萤光介虫科的Cypria crenulata和泥介虫科的Ilyocypris. angulata同时与腺介虫科其它动物聚为一支.     

基于18S rDNA序列研究腺介虫亚目系统5发育关系

基于1720 bp 的18S rRNA 基因序列以 Darwinula sp．和 Cytherelloidea．munechikai 为外群,采用最大简约法(MP 法)和邻接法(NJ 法)对腺介虫亚目(Cypridocopina)3总科5科9种动物的系统发育关系进行了分析．结果表明：1)现生腺介虫亚目动物为单系群；2)两种营海水生活的介形类—海介虫总科(Pontocypridoidea)和大介虫总科(Macrocypridoidea)间的亲缘关系较近；3)现生腺介虫总科(Cypridoidea)也为单系群,但该总科内各科间关系较复杂,主要分为两支,其中腺介虫科的 Dolerocypris sp．与萤光介虫科的 Candona holzkanpfi 聚成一支；而萤光介虫科的 Cypria crenulata 和泥介虫科的 Ilyocypris．angulata 同时与腺介虫科其它动物聚为一支．     

城市不同土地利用类型下土壤动物的分布初探

以上海市徐汇区为例,探讨了在农田、废弃地和绿地三种不同土地利用类型下土壤动物的分布特点.调查期间共获得大、中、小型土壤动物2006个,共25个类群.在农田中,弹尾类、螨类是优势类群;在废弃地中,双翅类幼虫、螨类、弹尾类和线虫类属于优势类群;绿地中,线蚓类、弹尾类为优势类群.线蚓类、螨类和弹尾类在农田、废弃地和绿地中同时出现的概率要大于其他类群,表现为弹尾类>螨类>线蚓类.在群落结构方面,废弃地中的优势度指数在几个月份中一直低于其他两种类型;绿地优势度指数比较高,均匀性指数和多样性指数不高;而农田10,11月的优势度指数高于绿地.     

Affinities of 'hyopsodontids' to elephant shrews and a Holarctic origin of Afrotheria

Macroscelideans (elephant shrews or sengis) are small-bodied (25-540 g), cursorial (running) and saltatorial (jumping), insectivorous and omnivorous placental mammals represented by at least 15 extant African species classified in four genera. Macroscelidea is one of several morphologically diverse but predominantly African placental orders classified in the superorder Afrotheria by molecular phylogeneticists. The distribution of modern afrotheres, in combination with a basal position for Afrotheria within Placentalia and molecular divergence-time estimates, has been used to link placental diversification with the mid-Cretaceous separation of South America and Africa. Morphological phylogenetic analyses do not support Afrotheria and the fossil record favours a northern origin of Placentalia. Here we describe fossil postcrania that provide evidence for a close relationship between North American Palaeocene-Eocene apheliscine 'hyopsodontid' 'condylarths' (early ungulates or hoofed mammals) and extant Macroscelidea. Apheliscine postcranial morphology is consistent with a relationship to other ungulate-like afrotheres (Hyracoidea, Proboscidea) but does not provide support for a monophyletic Afrotheria. As the oldest record of an afrothere clade, identification of macroscelidean relatives in the North American Palaeocene argues against an African origin for Afrotheria, weakening support for linking placental diversification to the break-up of Gondwana.     

医蛭形亚目常见物种系统发育基因组学研究

本研究基于GenBank中10个医蛭形亚目物种及2个近缘外类群的基因组或转录组数据,提取COI、18 S和蛋白编码核基因的直系同源序列（Orthologs）,开展系统发育分析。比对后的COI、18 S和Orthologs序列长度分别为1533、1832、220095 bp。最大似然法和贝叶斯推断法分析显示,基于Orthologs序列构建的系统发育树在几乎所有节点上的支持率都达到100%,明显优于COI和18 S序列得到的结果。研究表明,医蛭科的欧洲医蛭、东方医蛭和侧纹医蛭组成一个单系群,医蛭科的日本医蛭与黄蛭科的宽体金线蛭和尖细金线蛭组成另一单系群,而黄蛭科的马蛭与上述6个物种形成姐妹群。医蛭科的两种牛蛭（菲牛蛭和棒纹牛蛭）组成一个单系群,此单系群与医蛭科的其他物种的遗传关系比马蛭更疏远;山蛭科的洞穴山蛭在10个医蛭形亚目种类中处于最基部位置。本研究阐明了医蛭形亚目常见物种的系统发育关系,为这些物种的资源开发利用和保护提供科学依据。     

The discovery of aeschnidiid nymphs (Aeschnidiidae, Odonata, Insecta)

Aeschnidiid nymphs are here first identified and described, and its phylogenetic relationship and bioecological characteristics are deduced. The nymphs known from China, Mongolia, Russia and Brazil and arranged in the family Aeschnidiidae are, in fact, unrelated to this group. All the known five Chinese species in four genera which were erected based on fossil nymphs and placed in the family Gomphidae may be transferred in Aeschnidiidae and merged into one alone, theSinaeschnidia cancellosa. It is a geographically widespread species from the “Jehol biota” of East Asia and appeared in the latest Late Jurassic age.     

中国斑翅蝗科(直翅目:蝗总科)11属的系统发育关系支序分析

在比较形态学研究的基础上，本文选择了25个性状，利用Hennig86程序包，以支序分析探讨了中国斑翅蝗科11属昆虫间的系统发育关系，结果表明：斑翅蝗科11属昆虫可分为3支：由小车蝗属(11)与车蝗属(4)和飞蝗属(5)这一对姐妹群组成第1支，相互间关系不明确的尖翅蝗属(9)和绿纹蝗属(10)组成第2支，剩余的赤翅蝗属(12)、束颈蝗属(14)、疣蝗属(13)、异痴蝗属(6)、痴蝗属(7)及皱膝蝗属(8)6属构成第3支，其中痴蝗属与皱膝蝗属为1对姐妹群，它俩的最近共同祖先与异痴蝗属构成姐妹群关系，然后依次与疣蝗属、束颈蝗属、赤翅蝗属分别构成关系上渐远的单系群，它们的亲缘关系可表示为：((11(4，5))(9，10(12(14(13(6(7，8)))))))。     

Investisations into the perplexing interrelationship of the Genus Takifugu Abe, 1949 （Tetraodontiformes,Tetraodontidae）

The phylogenetic relationships within the genus Takifugu Abe, 1949 （Tetraodontiformes, Tetraodontidae） remain unresolved. Because of the use of Takifugu as model organisms, the resolution of these relationships is crucial for the interpretation of evolutionary trends in biology. Pufferfishes of this genus are comprised of a comparatively small number of species and are mainly distributed along the coastal region of the western part of the Sea of Japan and the coastline of China. Mitochondrial gene sequences were employed to test the phylogenetic hypotheses within the genus. Seventeen species of the genus were examined. Molecular phylogenetic trees were constructed using the maximum parsi- mony, neighbor-joining, maximum likelihood and Bayesian methods. Our hypothesis of internal relationships within the genus differs from previous hypotheses. Our results indicate that （1） the genus Takifugu is a monophyletic assemblage; （2） the genus is divided into 6 subgroups based on the moecular data; and （3） there is low genetic diversity among the species within this genus. In addition, speciation within Takifugu appears to be driven by hybridization and isolation by distribution. Our results also suggested that the taxonomy in the genus should be clarified based on both molecular and morphological data.     

A complete insect from the Late Devonian period

After terrestrialization, the diversification of arthropods and vertebrates is thought to have occurred in two distinct phases, the first between the Silurian and the Frasnian stages (Late Devonian period) (425-385?million years (Myr) ago), and the second characterized by the emergence of numerous new major taxa, during the Late Carboniferous period (after 345?Myr ago). These two diversification periods bracket the depauperate vertebrate Romer's gap (360-345?Myr ago) and arthropod gap (385-325?Myr ago), which could be due to preservational artefact. Although a recent molecular dating has given an age of 390?Myr for the Holometabola, the record of hexapods during the Early-Middle Devonian (411.5-391?Myr ago, Pragian to Givetian stages) is exceptionally sparse and based on fragmentary remains, which hinders the timing of this diversification. Indeed, although Devonian Archaeognatha are problematic, the Pragian of Scotland has given some Collembola and the incomplete insect Rhyniognatha, with its diagnostic dicondylic, metapterygotan mandibles. The oldest, definitively winged insects are from the Serpukhovian stage (latest Early Carboniferous period). Here we report the first complete Late Devonian insect, which was probably a terrestrial species. Its 'orthopteroid' mandibles are of an omnivorous type, clearly not modified for a solely carnivorous diet. This discovery narrows the 45-Myr gap in the fossil record of Hexapoda, and demonstrates further a first Devonian phase of diversification for the Hexapoda, as in vertebrates, and suggests that the Pterygota diversified before and during Romer's gap.