碘泡科(粘体门:粘孢子纲:双壳目)动物的系统分类学研究

粘孢子虫是一类拥有广泛寄主的后生动物寄生虫,主要寄生于鱼类,并可引发病害,从而受到人们广泛的关注。但其基础研究还不够深入,在分类地位和分类系统方面存在着许多争议。而碘泡科是粘孢子虫最大的一科,其在属级和种级阶元的归属问题上也一直备受争议。此类动物结构简单、种类繁多,依据传统的形态特征进行的分类并不十分准确,借助更为先进的显微技术和以及分子生物学、免疫学等方法的应用,其分类学研究取得了巨大进步。本文从碘泡科的种、属级阶元分类和方法学两个方面对国内外碘泡科物种系统分类学研究的现状进行了综述,对碘泡科各属的归类问题进行了梳理,并对一些容易混淆的种类进行了厘清,同时总结了应用于碘泡虫系统分类研究中的几种方法,以期为该科动物的系统分类和鱼类粘孢子虫病的防治提供基础资料。     

黄颡单尾虫(粘体门,双壳目)的重描述及基于28S rDNA和ITS-5.8S序列的系统地位分析

采用形态分类学方法与以28S rDNA和ITS-5.8S序列为基础的分子系统学研究方法,对采自嘉陵江重庆市磁器口江段的黄颡单尾虫Unicauda pelteobagrusMa,1998进行了形态学和分子生物学的研究。基于28S rDNA数据探讨了黄颡单尾虫以及单尾虫属与相邻种属粘孢子虫间的系统地位;基于5.8S rDNA数据比较分析了粘孢子虫的系统地位。补充了黄颡单尾虫重庆种群形态学信息和28S rDNA、ITS-5.8S rDNA序列的分子信息。     

绿藻门小球藻科的分类学研究进展

小球藻科物种生境范围广,分布于全球各种淡水、海水及陆生环境中,是多种生态系统的重要组成部分,且以其重要的科学和应用价值成为研究热点。由于个体微小及较强的形态可塑性,小球藻科物种能供分辨的形态特征有限,其经典分类学研究和物种鉴定存在诸多困难。随着基于DNA序列的研究方法在分类学研究中的应用,小球藻科历经多次修订,物种组成发生了很大变化,目前,小球藻科包含约48个属258个种。该科分类仍存在许多悬而未决的问题,如有些属、种的分类地位存疑、分类单元的多系起源问题、一些新支系有待进行物种归类。本文系统总结了小球藻科分类学研究历史和现状,并对其中存在的问题及存疑类群进行阐述,探讨了基因组学数据测序情况及其在分类学上的应用前景,以期为小球藻科的系统分类研究和开发利用提供基础参考资料。     

斑鳢和乌鳢寄生孢子虫的研究

关于寄生鳢属鱼类原生动物的研究,外国已有不少的文献,但在我国还没有关于这方面的资料。作者进行这一研究工作,目的是了解斑鳢(Ophiocephalus maculatus)和乌鳢(O.argus)两种淡水鱼的孢子虫种类的形态学,以及对寄主的关系,以供鱼病防治和有关寄生虫学方面工作者在理论和实践上的参考。本文记述的孢子虫共22种,其中已见于文献的6种,新种16种,并包括粘孢子虫一新属。其分类系统如下:     

我国淡水鱼类粘孢子虫的支序分类学研究

本研究选取15个主要特征对我国淡水鱼类23属粘孢子虫的支序分类进行了分析.结果表明,根据这15个特征构建的经典分支系统树与现有分类系统较为一致;而许多被分子系统学证明有争议的特征,如尾孢虫的尾突,孢子和极囊的形状等在研究粘孢子虫的系谱发育中仍然有着重要作用,剔除了上述特征的分支系统树与经典的分支系统树相比,存在许多缺陷.嗜碘泡是区分粘体虫和碘泡虫的主要特征,然而剔除嗜碘泡特征的分支系统树与经典的分支系统树区别不大,因此,我们建议在这一方面和国际学术界统一起来,即不再把嗜碘泡作为区分碘泡虫和粘体虫的主要特征.     

粘孢子虫免疫学研究进展

粘孢子虫(Myxosporean)除少数种类寄生在蠕虫、两栖类和爬行类外1,绝大部分寄生于鱼类(包括海水鱼类和淡水鱼类),可以说粘孢子虫是鱼类特有的一类寄生原生动物       

梧桐科分类学研究评述

梧桐科(Sterculiaceae)是锦葵目中的一个多型科,主要分布于热带和亚热带地区,只有少数种可分布到温带地区。由于该科植物的形态特征较为多样化,至今对于它的范围和所包含的属种数目在各国学者间仍没有达成共识。该文从梧桐科的分类地位和系统关系、属的分类地位和亲缘关系以及分类学新特征在梧桐科分类中的应用3个方面入手,分析了梧桐科分类学研究的历史、现状和存在的问题,特别是把来自分子资料的研究结果与传统分类进行了比较分析,试图为梧桐科的分类学研究提供更多的帮助。     

尼氏单极虫(粘体门,双壳目)重描述及基于18S rDNA系统地位分析

采用常规细胞学方法与18S rDNA序列比较的方法,对采自于重庆市嘉陵江段的粘孢子虫,尼氏单极虫Thelohanellus nikolskii进行了形态学和分子生物学的研究,此为首次在我国长江流域检获尼氏单极虫。本文在补充了尼氏单极虫中国种群18S rDNA序列信息的分析、比较基础上,探讨了该虫与相邻种属的系统关系,佐证了其分类学位置。     

鱼类粘孢子虫病及其对宿主种群的影响

粘孢子虫是寄生于水生动物的一类病原生物,能引起淡、海水养殖鱼及野生鱼类一系列严重的疾病,而且一经感染,宿主的几乎所有组织器官都将受到影响。这类疾病中,多种病的致病机理已得到很好的阐述。尽管死亡率极小,宿主的死亡是由于严重感染导致机体功能减退、对环境的应激或感染了一些继发病原体。关于自然状态下感染对宿主种群的影响尚不明了,几乎没有仅由粘孢子虫感染引起宿主大批死亡的情况。难以展示粘孢子虫病对宿主种群的影响是与缺乏合适的统计学工具和长期的数据积累有限有关。本文利用Taylor法则及变量与平均比率,对英国的某些河流系统进行研究。数据表明,鲤鱼慢性感染粘液丸虫与鲤科鱼类种群的减少有关     

鼢鼠亚科 Mysopalacinae动物系统学研究现状与展望

现生鼢鼠是分布于东亚的一类典型地下啮齿动物,中国西部是其多个种的模式产地和主要分布区域。该类动物分布广、数量多,经济和生态意义重要,有关其控制和管理问题长期存有困扰。有效的物种管理离不开分类及生态学知识,但学界对该类群的分类地位与系统发育关系等至今仍有争议。随着分子系统学等现代科学技术的发展,其系统发育和分类地位等产生了许多新的研究结果。本文对近年来鼢鼠现存种系统学方面取得的研究进展进行了梳理,综述了鼢鼠亚科动物各系统分类的观点及其主要依据,分析了一些存在的问题,并就如何进一步分类研究等提出了建议,旨在促进鼢鼠亚科动物系统分类学研究的发展,为该类群物种资源合理利用与管理等提供基础资料。     

Myxosporean infections in cultured tilapias in Israel

Five new species of myxosporean parasite are described from cultured tilapias in Israel. These are: Myxosoma sarigi, Myxosoma equatorialis, Myxobolus israelensis, Myxobolus agolus, and Myxobolus galilaeus. The first four were found in hybrids of Oreochromis aureus X Oreochromis niloticus while Myxobolus galilaeus was found in Sarotherodon galilaeus. In addition, M. sarigi, M. israelensis, and Myxobolus sp. were also found in S. galilaeus. In the light of the present study, the taxonomy of myxosporean infections in tilapias is modified. Mature spores may localize in the melano-macrophage centers of the spleen and kidney where they may eventually be destroyed. No cases of mortality have so far been associated with these parasites.     

Myxosporean Infections in Cultured Tilapias in Israel1

Five new species of myxosporean parasite are described from cultured tilapias in Israel. These are: Myxosoma sarigi. Myxosoma equatorialis, Myxobolus israelensis. Myxobolus agolus, and Myxobolus galilaeus. The first four were found in hybrids of Oreochromis aureus x Oreochromis niloticus while Myxobolus galilaeus was found in Sarolherodon galilaeus. In addition, M. sarigi. M. israelensis, and Myxobolus sp. were also found in S. galilaeus. In the light of the present study, the taxonomy of myxosporean infections in tilapias is modified. Mature spores may localize in the melano-macrophage centers of the spleen and kidney where ihey may eventually be destroyed. Nc cases of mortality have so far been associated with these parasites.     

Present knowledge on the life cycle,taxonomy, pathology,and therapy of some Myxosporea spp. important for freshwater fish

In this review some important myxosporean species of fish are depicted and described, with special reference to Myxobolus cerebralis (causing whirling disease of salmonids), Sphaerospora renicola (causing Swimbladder inflammation of common carp), Hoferellus carassii (causing kidney enlargement disease of goldfish and proliferative kidney disease [PKD] of salmonids). Detailed information on the life cycles of M. cerebralis, M. cotti, and M. pavlovskii is presented proving that these myxosporeans develop in an intermediate host, the oligochaete worm, Tubifex tubifex to actinosporeans which represent the only infective stage for susceptible fish. These findings imply that the present taxonomy for the phylum Myxozoa has to be revised. Trends for treatment of myxosporean associated diseases are summarized with special emphasis on the antibiotic Fumagillin DCH.     

The phylogeny of Myxosporea (Myxozoa) based on small subunit ribosomal RNA gene analysis

The phylogeny of the Myxosporea was studied using the small-subunit ribosomal RNA gene sequences. Maximum parsimony and Bayesian inference were used to determine myxosporean phylogenetic relationships. The analysis included 120 myxosporean sequences retrieved from GenBank and 21 newly obtained sequences of myxosporeans representing nine genera. Members of the genera Palliatus and Auerbachia were sequenced for the first time. The phylogenetic analysis supported a split of myxosporeans into two main lineages separating most of freshwater species from marine ones as described by previous authors. In addition to the two main lineages, a third lineage consisting of three species was found (Sphaerospora truttae, Sphaerospora elegans and Leptotheca ranae) and additional exceptions to the marine/freshwater myxosporean split were recognised (Sphaeromyxa hellandi, Sphaeromyxa longa and Myxidium coryphaenoideum). All three myxosporean lineages were characterised by specific lengths of SSU rDNA sequences. The lineage of marine myxosporeans split into five well-defined clades. They consisted of species with a similar site of infection and spore morphology and were referred as the Parvicapsula clade, the Enteromyxum clade, the Ceratomyxa clade, the marine Myxidium clade and the Kudoa clade, respectively. The inner topology of the freshwater clade was more complex but the trend to branch according to site of infection was observed in this clade as well. Due to the number of sequences available, a histozoic (Myxobolus clade) predominated. Interestingly, five morphologically different species infecting urinary bladder clustered within the histozoic (Myxobolus) clade. The phylogenetic trees derived from this study differ in a number of respects from the current taxonomy of the myxosporeans, which suggests that several currently utilised characters may be homoplasious or that reliance on a single gene tree may not adequately reflect the phylogeny of the group.     

我国直翅目昆虫细胞分类学研究现状

从研究材料、研究方法、染色体研究在昆虫分类上的应用 3个方面对我国昆虫尤其是直翅目昆虫的细胞分类学研究情况作了简要的概述 ,并着重论述了直翅目昆虫的核型及带型的研究现状 ,同时对我国直翅目昆虫分类学的发展前景进行了展望     

丛枝菌根真菌系统分类及群落研究技术进展

丛枝菌根真菌（AMF）是自然生态系统重要的组成部分,能与植物根系形成互惠共生体.传统的AMF分类主要依赖于对土壤无性孢子的形态鉴定,具有一定的局限性.近年来基于核酸分析的分子鉴定技术使AMF的分类更具科学性和准确性,补充和完善了基于孢子形态鉴定所建立的分类系统.AMF群落研究依赖于AMF的分类鉴定,主要包括孢子形态鉴定和分子生物学分析两类研究法.本文综述了AMF的分类系统和群落研究方法,着重介绍了近年来应用较多的AMF群落研究的分子生物学技术.作者认为,采取形态与分子相结合的办法将有助于推动AMF群落研究和AMF自然分类系统的建立和完善.     

近代鸟类分类与系统发育研究进展

简要综述了宏观和微观领域的鸟类分类学研究进展.宏观领域介绍了传统形态分类学、数值分类学和支序分类学,结合鸣声分析强调支序分类学的应用.微观领域介绍了Sibley分类系统和近年来出现的主要基于mtDNA的鸟类系统学研究.通过对大量研究工作的分析提出该领域今后应进行综合性研究.     

菌物分类学研究中常见的物种概念

物种是生物多样性与分类学研究的基本单元, 物种识别是生物学研究的基本问题之一。物种的划分一直以来都没有一个明确统一的标准, 这使得分类学多少带有主观的色彩, 并经常被看作艺术而不完全是科学的研究。本文简要概述了菌物分类学研究中常见的3个物种概念, 即形态学种、生物学种和系统发育学种的背景和应用现状, 并通过实例讨论了这3个物种概念的特点及应用中存在的问题, 特别是各个物种概念之间的交错, 以期为菌物分类学研究和物种概念探讨提供参考。     

Integrative taxonomy,or iterative taxonomy?

The recently introduced term ‘integrative taxonomy’ refers to taxonomy that integrates all available data sources to frame species limits. We survey current taxonomic methods available to delimit species that integrate a variety of data, including molecular and morphological characters. A literature review of empirical studies using the term ‘integrative taxonomy’ assessed the kinds of data being used to frame species limits, and methods of integration. Almost all studies are qualitative and comparative – we are a long way from a repeatable, quantitative method of truly ‘integrative taxonomy’. The usual methods for integrating data in phylogenetic and population genetic paradigms are not appropriate for integrative taxonomy, either because of the diverse range of data used or because of the special challenges that arise when working at the species/population boundary. We identify two challenges that, if met, will facilitate the development of a more complete toolkit and a more robust research programme in integrative taxonomy using species tree approaches. We propose the term ‘iterative taxonomy’ for current practice that treats species boundaries as hypotheses to be tested with new evidence. A search for biological or evolutionary explanations for discordant evidence can be used to distinguish between competing species boundary hypotheses. We identify two recent empirical examples that use the process of iterative taxonomy.