有鳞目动物显微皮纹学

简要介绍了近年来国内外对有鳞目动物表皮扫描电镜研究的动态。现已描述了多样化的鳞片感觉器官;明确了有鳞目动物表皮具有复杂的组织学层次结构;其中最重要的是证明了表皮几丁质双层排列的事实以及得杂的蜕皮循环。研究还表明由于鳞片表皮结构特征在高级分类阶元中具有保守性,因而可以提供有用的系统演化信息。至少某些表皮特征,如微饰类型反映了系统联系而非生态适应。     

杉科、柏科的系统发生关系研究进展

杉科、柏科是松柏类裸子植物中的重要类群,其系统分类研究一直是裸子植物的研究热点之一.但是杉科与柏科之间及其内部各属之间的系统发生关系却一直存在争议.一般认为杉科、柏科单独成科.近年来的分子系统学及分支系统学研究结果证实:除了金松属以外,杉科和柏科为一单系群,应合并为一个科Cupres-saceae sensu　lato（广义柏科）,其主要分支类群的系统发生关系也已经基本确立,而金松属则单独成立金松科.     

中国爬行纲动物分类厘定

本文对中国爬行纲动物的分类体系和物种进行了系统的评估, 规范了中文学名, 给出了《中国爬行纲校正名录》, 结果表明: 中国现存爬行纲动物3目30科132属462种, 其中鳄形目(Crocodylia)1科1属1种, 龟鳖目(Testudines)6科18属33种, 有鳞目(Squamata)蜥蜴亚目(Lacertilia)10科41属189种, 有鳞目蛇亚目(Serpentes)13科72属239种。与《中国动物志 爬行纲 第一卷(总论、龟鳖目、鳄形目)》、《中国动物志 爬行纲 第二卷(有鳞目: 蜥蜴亚目)》和《中国蛇类》相比, 目和亚目无变化; 科级水平新增5科, 变更2科; 属级水平新增23属, 合并15属, 变更6属; 种级水平新增81种, 变动2种; 未收录同物异名12种、杂交6种、中国无分布7种。形态和分子系统发育研究结果在爬行动物不同分类阶元均有一定差异, 文章对这些争议进行了讨论, 并对名录的选择做了说明。     

苔藓动物的起源与系统发生研究进展—形态学和分子生物学的证据

苔藓动物是后生动物中的一个重要类群。然而,和其它主要后生动物类群相比,长期以来对它的系统学研究却相对滞后。其起源,系统发生地位以及与其它后生物门类之间、其内部各高级分类群间的谱系发生关系一直存在争议。一般认为它是介于原口动物和后口动物之间的过渡类群。但是,近年来的分子系统学研究已经证实了它的原口归属。古生物学资料表明,虽然苔藓动物的大多数类群在奥陶纪已经分化出来,但它在寒武纪却缺乏任何化石记录。另外,苔藓动物起源的时间和方式、其内部各类群间的系统发生关系特别是现生类群和化石类群之间的关系等诸多问题的解决,还有待于大量的形态学和不同的分子数据的进一步积累,并结合其地层分布等各种相关资料进行综合研究。     

大头蛙和脆皮大头蛙线粒体3个基因的测定及两栖类亲缘关系研究

现存的两栖类系统发生关系一直存在争议,特别是3个目间的亲缘关系。本文设计了5对引物,扩增和测定了大头蛙和脆皮大头蛙线粒体12S和16S rRNA基因和Cytb基因的全序列。在对所测序列进行分析的同时,基于3个基因全序列的相加数据,运用MEGA 3.1和PHYLIP 3.64软件中的NJ法、MP法和ML法,对两爬类17个物种,以鱼类非洲肺鱼为外群,重建出3个树形完全一致的分子系统树。研究结果显示:现存两栖类中无尾目和有尾目为姐妹群关系,并推断有尾目内小鲵科和隐鳃鲵科亲缘关系较近。此外,在研究两栖类系统发生关系方面,作者分析前人研究中产生两种不同观点的可能原因,同时总结了在此类研究中产生偏差的几种影响因素。     

鸡形目鸟类系统发生研究现状

综合形态学、行为学、分子系统发生等方面研究成果,对世界鸡形目鸟类科的系统关系以及属、种间系统发生的研究进展进行了阐述,侧重介绍与我国鸡形目鸟类相关类群的系统发生研究现状。与传统的系统关系比较,新的研究结果主要有:凤冠雉科和冢雉科不再是互为姊妹群;传统分类中的雉族和鹑族被证明并非单源而是多源的;雉族的原鸡属与鹑族的竹鸡属有很近的亲缘关系;灰山鹑、火鸡和松鸡类的系统发生关系可能很近。分子进化的研究表明雉科各属的起源主要集中在上新世。     

爬行动物的生殖

爬行动物是最早出现的真正陆栖脊椎动物 ,是完全适应陆地生活的类群。为了适应特殊和复杂的陆上生活环境 ,爬行动物在一些器官系统的组成和机能方面或多或少地发生了一些改变 ,其生殖系统也不例外。1　雄性交接器官　在生殖季节 ,爬行动物全部种类毫无例外地都要在陆地上或由水登陆进行繁殖 ,行体内受精。为了保证体内受精的顺利完成 ,在生殖系统的组成上爬行动物雄性发展了交接器官。但是不同的类群在雄性交接器官的形态和结构上有所不一样。爬行动物现生种类有 4目 :龟鳖目、鳄形目、喙头蜥目和有鳞目 ,除了分布于新西兰的喙头蜥目 (仅含…     

圆网蛛类系统发生与网型进化

本文从妖面蛛总科和园蛛总科系统发生关系、园蛛总科网型不同的蜘蛛间的系统发生关系及蛛网构建行为等几个方面着重介绍了圆网蛛类系统发生及网型进化的研究进展.圆网蛛类系统发生与其网型进化有效地结合、进行综合研究将有助于圆网蛛类的起源及网型多样性的研究.     

用线粒体tRNA基因探讨现存两栖动物三个目间系统发生关系

现存两栖类3个目的系统发生关系仍然没有统一意见,最广泛被接受的假说是单系起源,并且无尾类和有尾类为姐妹群关系而排斥蚓螈类(蛙类假说)。然而,这一假说一直存在争议。我们在测定了泽蛙线粒体基因组全序列的基础上,与已知其他的6种两栖类进行详细的比较分析,同时选择了11种高等脊椎动物的线粒体全基因序列,以硬骨鱼类作外群,用22个tRNA基因合并数据进行系统发生重建分析,结果表明MP、ML树都强力地支持现生两栖类动物为单系群,并且有尾目和蚓螈目为姐妹群关系。这个结果与蛙类假说是相矛盾的,与Bolt(1991)在形态学基础上提出的有尾类和蚓螈类为姐妹群关系的假说相一致,并得到建立在线粒体和核rRNA基因数据基础上的许多分子研究的支持。另外还探讨了本结果与前人的研究不一致的原因,以及利用线粒体全基因序列进行系统发生分析可能存在的偏差。     

湖北省爬行类新记录——棕黑腹链蛇

笔者于2006年7月在湖北省广水市大贵寺林场进行动物资源考察时,采集到一批蛇类标本,经鉴定其中4条为棕黑腹链蛇Amphiesma sauteri,为湖北省爬行类新纪录.棕黑腹链蛇在分类上隶属爬行纲、有鳞目、蛇亚目、游蛇科、腹链蛇属.标本保存于华中师范大学动物学研究室.     

Molecular evolution of Bov-B LINEs in vertebrates

Since their discovery in family Bovidae (bovids), Bov-B LINEs, believed to be order-specific SINEs, have been found in all ruminants and recently also in Viperidae snakes. The distribution and the evolutionary relationships of Bov-B LINEs provide an indication of their origin and evolutionary dynamics in different species. The evolutionary origin of Bov-B LINE elements has been shown unequivocally to be in Squamata (squamates). The horizontal transfer of Bov-B LINE elements in vertebrates has been confirmed by their discontinuous phylogenetic distribution in Squamata (Serpentes and two lizard infra-orders) as well as in Ruminantia, by the high level of nucleotide identity, and by their phylogenetic relationships. The direction of horizontal transfer from Squamata to the ancestor of Ruminantia is evident from the genetic distances and discontinuous phylogenetic distribution of Bov-B LINE elements. The ancestor of Colubroidea snakes has been recognized as a possible donor of Bov-B LINE elements to Ruminantia. The timing of horizontal transfer has been estimated from the distribution of Bov-B LINE elements in Ruminantia and the fossil data of Ruminantia to be 40-50 My ago. The phylogenetic relationships of Bov-B LINE elements from the various Squamata species agrees with that of the species phylogeny, suggesting that Bov-B LINE elements have been stably maintained by vertical transmission since the origin of Squamata in the Mesozoic era.     

Horizontal transfer of non-LTR retrotransposons in vertebrates

Since their discovery in family Bovidae (bovids), Bov-B LINEs, believed to be order-specific SINEs, have been found in all ruminants and recently also in Viperidae snakes. The distribution and the evolutionary relationships of Bov-B LINEs provide an indication of their origin and evolutionary dynamics in different species. The evolutionary origin of Bov-B LINE elements has been shown unequivocally to be in Squamata (squamates). The horizontal transfer of Bov-B LINE elements in vertebrates has been confirmed by their discontinuous phylogenetic distribution in Squamata (Serpentes and two lizard infra-orders) as well as in Ruminantia, by the high level of nucleotide identity, and by their phylogenetic relationships. The direction of horizontal transfer from Squamata to the ancestor of Ruminantia is evident from the genetic distances and discontinuous phylogenetic distribution of Bov-B LINE elements. The ancestral snake lineage (Boidae) has been recognized as a possible donor of Bov-B LINE elements to Ruminantia. The timing of horizontal transfer has been estimated from the distribution of Bov-B LINE elements in Ruminantia and the fossil data of Ruminantia to be 40–50mya. The phylogenetic relationships of Bov-B LINE elements from the various Squamata species agrees with that of the species phylogeny, suggesting that Bov-B LINE elements have been stably maintained by vertical transmission since the origin of Squamata in the Mesozoic era. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of taxon sampling on recovering the phylogeny of squamate reptiles based on complete mitochondrial genome and nuclear gene sequence data

The complete nucleotide sequences of the mitochondrial (mt) genomes of three species of squamate lizards: Blanus cinereus (Amphisbaenidae), Anguis fragilis (Anguidae), and Tarentola mauritanica (Geckkonidae) were determined anew. The deduced amino acid sequences of all 13 mt protein-coding genes were combined into a single data set and phylogenetic relationships among main squamate lineages were analyzed under maximum likelihood (ML) and Bayesian Inference (BI). Within Squamata, the monophyly of Iguanidae, Anguimorpha, Amphisbaenia, Gekkota, Serpentes, and Acrodonta received high statistical support with both methods. It is particularly striking that this is the first molecular analysis that recovers the monophyly of Scincomorpha (including Scincidae, Xantusiidae, Cordylidae, and Lacertidae), although it is only supported in the Bayesian analysis, and it is sensitive to changes in the outgroup (see below). Phylogenetic relationships among the main squamate lineages could not be resolved with ML but received strong support with BI (above 95%). The newly reconstructed phylogeny of squamates does not support the Iguania-Scleroglossa split. Acrodonta and Serpentes form a clade, which is the sister group of the remaining squamate lineages. Within these, Gekkota were the first branching out, followed by Amphisbaenia, and a clade including Anguimorpha as sister group of Scincomorpha + Iguanidae. The recovered topology differed substantially from previously reported hypotheses on squamate relationships, and the relative effect of using different outgroups, genes, and taxon samplings were explored. The sister group relationship of Serpentes + Acrodonta, and their relative basal position within Squamata could be due to a long-branch attraction artifact. Phylogenetic relationships among Scincomorpha, Amphisbaenia, and Anguimorpha were found to be rather unresolved. Future improving of squamate phylogenetic relationships would rely on finding snake and acrodont species with slower mt evolutionary rates, ensuring thorough taxon coverage of squamate diversity, and incorporating more nuclear genes with appropriate evolutionary rates.     

Cyprinid phylogeny based on Bayesian and maximum likelihood analyses of partitioned data: implications for Cyprinidae systematics

Cyprinidae is the biggest family of freshwater fish, but the phylogenetic relationships among its higher-level taxa are not yet fully resolved. In this study, we used the nuclear recombination activating gene 2 and the mitochondrial 16S ribosomal RNA and cytochrome b genes to reconstruct cyprinid phylogeny. Our aims were to (i) demonstrate the effects of partitioned phylogenetic analyses on phylogeny reconstruction of cyprinid fishes; (ii) provide new insights into the phylogeny of cyprinids. Our study indicated that unpartitioned strategy was optimal for our analyses; partitioned analyses did not provide better-resolved or -supported estimates of cyprinid phylogeny. Bayesian analyses support the following relationships among the major monophyletic groups within Cyprinidae: (Cyprininae, Labeoninae), ((Acheilognathinae, ((Leuciscinae, Tincinae), Gobioninae)), Xenocyprininae). The placement of Danioninae was poorly resolved. Estimates of divergence dates within the family showed that radiation of the major cyprinid groups occurred during the Late Oligocene through the Late Miocene. Our phylogenetic analyses improved our understanding of the evolutionary history of this important fish family.     

Evidence for Gondwanan vicariance in an ancient clade of gecko lizards

Aim Geckos (Reptilia: Squamata), due to their great age and global distribution, are excellent candidates to test hypotheses of Gondwanan vicariance against post‐Gondwanan dispersal. Our aims are: to generate a phylogeny of the sphaerodactyl geckos and their closest relatives; evaluate previous phylogenetic hypotheses of the sphaerodactyl geckos with regard to the other major gecko lineages; and to use divergence date estimates to inform a biogeographical scenario regarding Gondwanan relationships and assess the roles of vicariance and dispersal in shaping the current distributions of the New World sphaerodactyl geckos and their closest Old World relatives. Location Africa, Asia, Europe, South America, Atlantic Ocean. Methods We used parsimony and partitioned Bayesian methods to analyse data from five nuclear genes to generate a phylogeny for the New World sphaerodactyl geckos and their close Old World relatives. We used dispersal–vicariance analysis to determine ancestral area relationships among clades, and divergence times were estimated from the phylogeny using nonparametric rate smoothing. Results We recovered a monophyletic group containing the New World sphaerodactyl genera, Coleodactylus, Gonatodes, Lepidoblepharis, Pseudogonatodes and Sphaerodactylus, and the Old World Gekkotan genera Aristelliger, Euleptes, Quedenfeldtia, Pristurus, Saurodactylus and Teratoscincus. The dispersal–vicariance analysis indicated that the ancestral area for this clade was North Africa and surrounding regions. The divergence between the New World spaherodactyl geckos and their closest Old World relative was estimated to have occurred c. 96 Myr bp . Main conclusions Here we provide the first molecular genetic phylogenetic hypothesis of the New World sphaerodactyl geckos and their closest Old World relatives. A combination of divergence date estimates and dispersal–vicariance analysis informed a biogeographical scenario indicating that the split between the sphaerodactyl geckos and their African relatives coincided with the Africa/South America split and the opening of the Atlantic Ocean. We resurrect the family name Sphaerodactylidae to represent the expanded sphaerodactyl clade.     

Phylogeny of the water strider genus Rheumatobates (Heteroptera: Gerridae)

The genus Rheumatobates comprises thirty‐seven species and subspecies of New World water striders belonging to subfamily Rhagadotarsinae. Among species, males vary dramatically in the degree and nature of modifications of the antennae, three pairs of legs and abdominal and genital segments. Characters describing this modification have traditionally been used to differentiate and group species. The general assumption has been that modified species belong to one group and unmodified species to another. These two ‘species groups’ are subdivided into ‘subgroups’, but little effort has been made to resolve relationships among them. We conduct the first numerical cladistic analysis of Rheumatobates using a data set comprised of 102 characters, primarily describing modification of male external morphology. To address concerns about the inclusion of characters to be optimized on the phylogeny, characters describing modification of antennae and hind legs were included and then excluded in separate analyses. A preferred phylogeny was chosen from the four equally parsimonious cladograms found after successive reweighting of characters. There was good resolution at all levels of the phylogeny. Most of the major clades and terminal relationships were moderately to strongly supported, whereas the basal relationships were less well supported. The general assumption that unmodified and modified species form two monophyletic groups was not supported. However, traditionally recognized ‘subgroups’ within the modified species group were largely upheld. The analysis also suggested several major clades and relationships among these clades that were not previously recognized. The exclusion of characters describing modification of antennae and hind legs did not change the resolved major clades of the reconstructed phylogeny.     

Satellite DNA restriction site variability as a molecular basis of taxonoprint method: evidence from the study of Caucasian rock lizards

The restriction site distribution in satellite DNA of 17 Caucasian rock lizard species of the genus Lacerta (Darevskia gen. nov.), (Squamata, Lacertidae) was analyzed. The distribution patterns were shown to reflect the degree of satellite DNA evolutionary divergence, which could be revealed by taxonprint method, i.e., through the analysis of genomic DNA with a set of restriction endonucleases and subsequent computer-aided treatment. Thus, the taxonprint method offers an opportunity to examine the satellite DNA divergence in closely related species and infer their phylogeny of the species studied without reserting to costly and labor-consuming procedures. This is the advantage of using this technique at the early stages of genomic DNA phylogenetic analysis for rapid and effective estimation of relationships between closely related species as well as in the cases when DNA cloning and sequencing are too expensive or not feasible.     

Polymorphism in the sperm ultrastructure among four species of lizards in the genus Tupinambis (Squamata: Teiidae)

We describe, for the first time, the ultrastructure of the spermatozoa of four species of the genus Tupinambis (Squamata, Teiidae). We identified seven polymorphic characters within this genus: the presence and shape of the perforatorial base plate, the presence of the epinuclear lucent zone, the presence of a unilateral ridge in the acrosome, the presence of a central density within the proximal centriole, the number of mitochondria and dense-bodies sets, and the shape of mitochondria. We analysed the evolution of the seven polymorphic characters by mapping them onto a current phylogeny of the species of Tupinambis , using the teiids Ameiva ameiva and Cnemidophorus sexlineatus as outgroups. Our results indicate that sperm ultrastucture characters, although of great value for phylogeny at higher taxonomic levels in reptiles and other groups, are poor predictors of phylogeny when considering the species of Tupinambis studied here. We failed to identify evidences that homoplasy in sperm ultrastructure among the species of Tupinambis is due to convergent adaptation, suggesting that the polymorphism may be selectively neutral in this group.     

The phylogeny of squamate reptiles (lizards, snakes, and amphisbaenians) inferred from nine nuclear protein-coding genes

Squamate reptiles number approximately 8000 living species and are a major component of the world's terrestrial vertebrate diversity. However, the established relationships of the higher-level groups have been questioned in recent molecular analyses. Here we expand the molecular data to include DNA sequences, totaling 6192 base pairs (bp), from nine nuclear protein-coding genes (C-mos, RAG1, RAG2, R35, HOXA13, JUN, alpha-enolase, amelogenin and MAFB) for 19 taxa representing all major lineages. Our phylogenetic analyses yield a largely resolved phylogeny that challenges previous morphological analyses and requires a new classification. The limbless dibamids are the most basal squamates. Of the remaining taxa (Bifurcata), the gekkonids form a basal lineage. The Unidentata, squamates that are neither dibamids nor gekkonids, are divided into the Scinciformata (scincids, xantusiids, and cordylids) and the Episquamata (remaining taxa). Episquamata includes Laterata (Teiformata, Lacertiformata, and Amphisbaenia, with the latter two joined in Lacertibaenia) and Toxicofera (iguanians, anguimorphs and snakes). Our results reject several previous hypotheses that identified either the varanids, or a burrowing lineage such as amphisbaenians or dibamids, as the closest relative of snakes. Our study also rejects the monophyly of both Scleroglossa and Autarchoglossa, because Iguania, a species-rich lineage (ca. 1440 sp.), is in a highly nested position rather than being basal among Squamata. Thus iguanians should not be viewed as representing a primitive state of squamate evolution but rather a specialized and successful clade combining lingual prehension, dependence on visual cues, and ambush foraging mode, and which feeds mainly on prey avoided by other squamates. Molecular time estimates show that the Triassic and Jurassic (from 250 to 150 Myr) were important times for squamate evolution and diversification.     

Comparative biology and the importance of cladistic classification: a case study from the sensory biology of squamate reptiles

Evolutionary taxonomy has all but succumbed to cladistic methodology, but it continues to exert considerable influence in the realm of higher classification. Some systematists accept cladistic methods in phylogeny inference, but allow paraphyly in formal classifications. Most important, however, many traditional classifications based on paraphyletic groups (e.g. 'Reptilia') remain in force, deeply entrenched in the literature. Cladists have argued that such paraphyletic classifications can mislead comparative biologists into false evolutionary generalizations, but this assertion has rarely, if ever, been supported by example. This paper provides a case study, illustrating in detail the influence of a traditional paraphyletic classification of squamate reptiles on the historical development of ideas regarding the evolution of sensory modes (chemoreception vs. vision) in the group. The paraphyletic classification is shown to have led to false generalizations and incorrect conclusions stemming directly from the fact that the classification did not reflect accurately the phylogeny of Squamata, particularly the cladistic relationships of Gekkota. This study provides direct evidence that evolutionary generalization must be rooted in the branching pattern of phylogeny and not the potentially arbitrary categorical ranks of traditional taxonomies. It further supports recent calls for a truly phylogenctic taxonomy that has as its philosophical core the concept of descent.