蜱类系统学研究进展

本文介绍了近年来蜱的编目和分类及系统发育和演化等方面的研究进展。对软蜱科(Argasidae)说明了属的变动;硬蜱科(Ixodidae)介绍了璃眼蜱亚科(Hyalomminae)和凹沟蜱亚科(Bothriocrotoninae)以及相应变动的属(新建的凹沟蜱属Bothriocroton和须角蜱属Cornupalpatum,合并的牛蜱属Boophilus、暗眼蜱属Anocentor和盲花蜱属Aponomma)。根据新的分类变更对已知种类进行了分析。至2006年,世界已知蜱类有3科18属897种,中国有2科10属119种。阐明了有关蜱类系统发育研究的主要观点,并讨论了其不足和有待深入研究的问题。目前,把形态学和分子生物学数据结合在一起的全证据方法,并结合蜱类和不同宿主之间的关系、动物地理学、古生物学以及比较寄生虫学的资料,成为解决蜱类系统发育问题的有效途径。     

蕨类植物起源与系统发生关系研究进展

蕨类植物是一群非常古老的植物,在其漫长的演化历史中丢失了大量的系统发生信息,因此重建其系统演化关系是蕨类植物学家所面临的重要任务之一。近年来的分子系统学研究已经确立了一些类群的系统关系,但现存的蕨类分类系统和系统发生关系还有很多谜团有待揭开。化石记录表明蕨类植物最早出现于大约4亿多年前,但大部分现代真蕨类缺少足够的化石证据。它们的起源时间和方式及其内部各类群的系统发生关系等诸多问题的解决,还有待于大量形态学和不同分子水平上的实验数据的进一步积累,并结合其直接的化石证据进行综合研究。     

蕨类植物起源与系统发生关系研究进展

蕨类植物是一群非常古老的植物,在其漫长的演化历史中丢失了大量的系统发生信息,因此重建其系统演化关系是蕨类植物学家所面临的重要任务之一.近年来的分子系统学研究已经确立了一些类群的系统关系,但现存的蕨类分类系统和系统发生关系还有很多谜团有待揭开.化石记录表明蕨类植物最早出现于大约4亿多年前,但大部分现代真蕨类缺少足够的化石证据.它们的起源时间和方式及其内部各类群的系统发生关系等诸多问题的解决,还有待于大量形态学和不同分子水平上的实验数据的进一步积累,并结合其直接的化石证据进行综合研究.     

蜱类分类系统的变更

随着分子生物学技术在蜱类研究中的应用,及对蜱类系统发生的深入研究,蜱的分类及命名发生了很大变更。而中国在这一领域的研究还停留在20世纪90年代,分类系统过时。文章对中国曾经采用的蜱类分类系统与现今世界上普遍认可的分类系统进行了详细比较,以期引起注意,从而促进蜱类系统学及其他研究领域的发展。     

蜱雄性附腺分泌物及其功能的研究进展

交配是蜱类繁殖过程的关键环节,诱发雌蜱发生一系列的生理变化,并最终产卵。蜱雄性附腺分泌物在交配过程中发挥着重要作用,具有保护、活化精子,促进受精、卵巢发育和卵黄发生的功能,并对雌蜱的生殖生理行为等产生影响,如诱导雌蜱快速吸血和加速产卵。本文在简要分析蜱雄性附腺结构和分泌物生化特性基础上,系统阐述了蜱雄性附腺分泌物中各种功能因子的研究现状,着重论述其在精子获能、诱导雌蜱吸血、促进雌蜱卵巢发育和卵黄发生等方面的进展,并对未来研究提出了展望,以期为此领域的研究拓展思路。     

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.     

蜱类卵黄发生研究进展

蜱是一类特殊的节肢动物,有关其生殖生理的研究远远落后于昆虫。卵黄发生直接影响蜱类的繁殖力,一直是蜱类生理学一个十分活跃的研究领域。目前,对蜱类卵黄发生的研究主要包括卵黄蛋白的纯化与鉴定,卵黄原蛋白的合成与调控,卵母细胞对卵黄原蛋白的摄取以及转变为卵黄蛋白的分子过程。蜱类卵黄发生受激素调控,激素的作用与作用激素的种类在硬蜱和软蜱中表现出较大差别。对蜱类卵黄发生了解得尚少,在许多方面需深入研究。     

从顶枝学说、中柱学说和子叶节区学说看维管植物的形态演化和起源

作者对当前植物形态学中与维管植物的形态演化和起源有着十分密切关系的顶枝学说,中柱学说与子叶节区学说进行了全面研究。并结合半个多世纪以来国际上著名的植物系统学家的维管植物分类系统,反复进行了比较和研究,对其中认为不妥之处提出了我们的见解,具体反映在文后的“维管植物系统的系统发育图”中。     

亚东璃眼蜱的延迟交配对吸血时间和生殖力的影响

蜱类种群密度的制约因素包括生物的和非生物的两类,分析和认识这些规律,对蜱类的防治上有重要意义。 蜱类的生殖是维持种群密度的重要一环。后肛沟类硬蜱的雌虫当吸附在宿主体时,由于某些原因可发生延迟交配现象。蜱类延迟交配对生育力的影响,在这方面的研究较少。本文为亚东璃眼蜱Hyalomma asiaticum kozlovi Olenev的延迟交配对吸血时间、饱食后的体重以及产卵量等的试验研究结果。     

被子植物起源和早期演化研究的回顾与展望

近年来,被子植物起源和早期演化研究,由于手段和技术的更新,资料大量积累,取得了许多重要进展,成为植物学领域的一大热点。本文对过去近五十年的研究作了回顾,并从分子系统学、分支系统学、花原基发生的形态学、花发育的分子遗传学及白垩纪花和其它生殖结构化石研究等五个方面对该领域在最近十几年的研究进展进行综述,最后,对今后如何开展这方面的工作作了简要评论。     

Zoogeography of the San Andreas Fault system: Great Pacific Fracture Zones correspond with spatially concordant phylogeographic boundaries in western North America

The purpose of this article is to provide an ultimate tectonic explanation for several well‐studied zoogeographic boundaries along the west coast of North America, specifically, along the boundary of the North American and Pacific plates (the San Andreas Fault system). By reviewing 177 references from the plate tectonics and zoogeography literature, I demonstrate that four Great Pacific Fracture Zones (GPFZs) in the Pacific plate correspond with distributional limits and spatially concordant phylogeographic breaks for a wide variety of marine and terrestrial animals, including invertebrates, fish, amphibians, reptiles, birds, and mammals. These boundaries are: (1) Cape Mendocino and the North Coast Divide, (2) Point Conception and the Transverse Ranges, (3) Punta Eugenia and the Vizcaíno Desert, and (4) Cabo Corrientes and the Sierra Transvolcanica. However, discussion of the GPFZs is mostly absent from the zoogeography and phylogeography literature likely due to a disconnect between biologists and geologists. I argue that the four zoogeographic boundaries reviewed here ultimately originated via the same geological process (triple junction evolution). Finally, I suggest how a comparative phylogeographic approach can be used to test the hypothesis presented here.     

鲤科鲌亚科鱼类的系统发育及动物地理学

以雅罗鱼亚科为外群,采用分支系统学的原理和方法对鲌亚科17个属(须鳊属除外)进行了系统发育和动物地理学的分析.结果表明,(1)鲌亚科这17个属为一个单系群,并由4个较小的单系群组成;(2)鲌亚科现在的地理分布格局除源自离散事件外,主要源于扩散事件.鲌亚科的特征演化还表明,东亚地区地质历史的反转演化和平行演化可能在鲌亚科系统发育过程中起了重要的作用.     

Novel genes exhibit distinct patterns of function acquisition and network integration

Background  

Genes are created by a variety of evolutionary processes, some of which generate duplicate copies of an entire gene, while others rearrange pre-existing genetic elements or co-opt previously non-coding sequence to create genes with 'novel' sequences. These novel genes are thought to contribute to distinct phenotypes that distinguish organisms. The creation, evolution, and function of duplicated genes are well-studied; however, the genesis and early evolution of novel genes are not well-characterized. We developed a computational approach to investigate these issues by integrating genome-wide comparative phylogenetic analysis with functional and interaction data derived from small-scale and high-throughput experiments.     

METAMODELS AND PHYLOGENETIC REPLICATION: A SYSTEMATIC APPROACH TO THE EVOLUTION OF DEVELOPMENTAL PATHWAYS

Molecular genetic analysis of phenotypic variation has revealed many examples of evolutionary change in the developmental pathways that control plant and animal morphology. A major challenge is to integrate the information from diverse organisms and traits to understand the general patterns of developmental evolution. This integration can be facilitated by evolutionary metamodels—traits that have undergone multiple independent changes in different species and whose development is controlled by well-studied regulatory pathways. The metamodel approach provides the comparative equivalent of experimental replication, allowing us to test whether the evolution of each developmental pathway follows a consistent pattern, and whether different pathways are predisposed to different modes of evolution by their intrinsic organization. A review of several metamodels suggests that the structure of developmental pathways may bias the genetic basis of phenotypic evolution, and highlights phylogenetic replication as a value-added approach that produces deeper insights into the mechanisms of evolution than single-species analyses.     

The evolution of parasite-defence grooming in ungulates

Grooming repertoires are exhibited by all terrestrial mammals, and removal of ectoparasites is an important ancestral and current function. Parasite‐defence grooming is regulated both by a central control mechanism (programmed grooming model) and by cutaneous stimulation from bites (stimulus‐driven model). To study the evolution of parasite‐defence grooming in ungulates, we compared species‐typical grooming behaviour with host morphology and habitat to test predictions of the programmed grooming model while taking into account phylogenetic relatedness. We observed grooming in 60 ungulate species at ectoparasite‐free zoological parks in which the confound of differential tick exposure was controlled for and stimulus‐driven grooming was ruled out. Concentrated‐changes tests indicated that sexually dimorphic grooming (in which breeding males groom less than females) has coevolved with sexual body size dimorphism, suggesting that intrasexual selection has favoured reduced grooming that enhances vigilance of males for oestrous females and rival males. Concentrated‐changes tests also revealed that the evolution of complex oral grooming (involving alternate use of both teeth and tongue) and adult allogrooming (whereby conspecifics oral groom body regions not accessible by self grooming) was concentrated in lineages inhabiting closed woodland or forest habitat associated with increased tick exposure, with such advanced grooming being most concentrated in Cervidae. Regression analyses of independent contrasts indicated that both host body size and habitat play a role in the evolution of species‐typical oral grooming rates, as previously reported. These results indicate that the observed grooming represents centrally driven grooming patterns favoured by natural selection in each lineage. This is the first phylogenetically controlled comparative study to report the evolution of parasite‐defence grooming behaviours in response to selection pressures predicted by the programmed grooming hypothesis. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 81 , 17–37.     

The major tick salivary gland proteins and toxins from the soft tick,Ornithodoros savignyi,are part of the tick Lipocalin family: implications for the origins of tick toxicoses

The origins of tick toxicoses remain a subject of controversy because no molecular data are yet available to study the evolution of tick-derived toxins. In this study we describe the molecular structure of toxins from the soft tick, Ornithodoros savignyi. The tick salivary gland proteins (TSGPs) are four highly abundant proteins proposed to play a role in salivary gland granule biogenesis of the soft tick O. savignyi, of which the toxins TSGP2 and TSGP4 are a part. They were assigned to the lipocalin family based on sequence similarity to known tick lipocalins. Several other tick lipocalins were also identified using Smith-Waterman database searches, bringing the tick lipocalin family up to 20. Phylogenetic analysis showed that most tick lipocalins group within genus-specific clades, suggesting that gene duplication and divergence of tick lipocalin function occurred after tick speciation, most probably during the evolution of a hematophagous lifestyle. TSGP2 and TSGP3 show high sequence identity and group terminal to moubatin, an inhibitor of collagen-induced platelet aggregation from the tick, O. moubata. However, no platelet aggregation inhibitory activity is associated with the TSGPs using ADP or collagen as agonists, suggesting that TSGP2 and TSGP3 duplicated after divergence of O. savignyi and O. moubata. This timing is supported by the absence of TSGP2-4 in the salivary gland extracts of O. moubata. The absence of TSGP2 and TSGP4 in salivary gland extracts from O. moubata correlates with the nontoxicity of this tick species. The implications of this study are that the various forms of tick toxicoses do not have a common origin, but must have evolved independently in those tick species that cause pathogenesis.     

Paradigms in tick evolution

The study of tick evolution may be classified into disciplines such as taxonomy and systematics, biogeography, evolution and development (evo-devo), ecology, and hematophagy. These disciplines overlap and impact each other to various extents. Advances in one field may lead to paradigm shifts in our understanding of tick evolution not apparent to other fields. The current study considers paradigm shifts that occurred, are in the process, or may occur in future for the disciplines that study tick evolution. Some disciplines have undergone significant changes, while others may still be developing their own paradigms. Integration of these various disciplines is essential to come to a holistic view of tick evolution; however, maturation of paradigms may be necessary before this vision can be attained.     

Developmental genetics and homology: a hierarchical approach

New advances in developmental genetics are providing a bridge to connect the study of development and evolution. The successful integration of these fields, however, is dependent on having a clear understanding of the concept of homology. Therefore, developmental genetic data must be placed within the context of the comparative method to provide insight into the evolutionary and developmental origins of traits. The comparative analysis of traits derived from several hierarchical levels (genes, gene expression patterns, embryonic origins and morphology) can potentially reveal scenarios of developmental integration, opportunity and constraint. Moreover, this approach has implications for resolving modern controversies surrounding the concept of homology.