【作者】 陈旭淼；

【导师】 宋微波；

【作者基本信息】 中国海洋大学 ， 水生生物学， 2013， 博士

【摘要】 纤毛虫原生动物是最复杂和最高等的单细胞真核生物，具有独特的接合生殖方式及不同功能的两种核型，在细胞生物学、发育与进化等领域具有重要的研究意义。近年来，利用现代活体观察和银染技术对长期模糊的类群进行充分的形态学鉴定；在厘清混乱的基础上，开展纤毛虫细胞发育与分化模式研究；并结合分子生物学手段，探讨纤毛虫系统发育与进化关系，是当今原生动物学研究领域中最活跃的核心内容之一。作者于2007至2011年期间，工作主要着眼于中国北黄海和南海沿岸的红树林、河流入海口、淡水以及土壤生境，进行纤毛虫区系研究，所涉及的广义腹毛类（尾柱类、排毛类、尖毛类/散毛类）为最复杂和高等的纤毛虫类群，具有重要细胞分化、系统演化意义。建立若干新阶元，并对已知种进行新种群的细致描摹；揭示一系列新的发生学现象；丰富所涉及类群核糖体小亚基SSU rRNA基因序列和RNA二级结构等分子信息。为探讨关键类群的种间鉴别、科属级界定，以及在系统进化上争议的解决、构建更合理的新系统等方面，提供全面的形态学、细胞发生学和分子系统学信息支持。主要创新性成果包括三个方面：1）细胞发生学部分：对12个具有重要细胞分化、类群进化和系统演化意义的代表种（来自3目6科不同发生型的未明类群），开展个体发育研究，主要包括：皮层结构/重要胞器的起源-分化、近祖-衍化特征分析以及模式建立；对迄今存在误释或不详的巴库虫属、后尾柱虫属、伪角毛虫属、伪尾柱虫属、小双虫属、圆纤虫属、硬膜虫属、赭尖虫属、棘毛虫属等9个属的细胞发生模式做出进一步的修正和补足，揭示了一系列新的发生学现象、澄清若干悬疑。对所涉及的各个科属，进行科/亚科内阶元的细胞发生特征分析和比较，对伪角毛虫科、巴库虫科的单源发生性的质疑给出个体发育模式的分析；对圆纤虫属及其形态相近类群间的系统关系厘定，给出细胞发生学特征的参考依据；对硬膜虫属的建立与其在棘尾虫亚科的系统地位，以及该科的单源发生性，从细胞发生学角度给出明确的支持。2）系统学部分：在核糖体小亚基SSU rRNA基因测序、序列分析和RNA二级结构预测基础上，结合形态学特征、细胞发生模式等信息，对伪角毛虫科进行了更为清晰的厘定和清理，将偏角毛虫属和趋角虫属移入尾柱虫科。对小双虫属、管膜虫属中来自GenBank的多个核糖体小亚基SSU rRNA基因序列，进行形态学信息的追踪和分子信息的细致分析，辨识可能存在的鉴定错误，对这两个属的分子信息做出可靠的清理。立足于迄今有关尾柱目纤毛虫形态学和细胞发生学研究，以及分子资料的积累，本工作综合利用形态学特征与细胞发生模式信息，通过对衍生性状的比较、分析，恢复和建立尾柱目纤毛虫的分支演化关系。并且，将这种分析方法与分子系统学研究相结合，首次应用于尾柱类纤毛虫的新系统构建和系统演化关系探讨。3）形态分类学部分：作为一个衍生成果，本文同时描述和建立了1新属（单冠虫属）、10新种（亚热带巴库虫、陈氏后尾柱虫、肉色单冠虫、爵氏单冠虫、赤色伪角毛虫、盐生伪尾柱虫、美丽小双虫、苍白小双虫、东方圆纤虫、亚热带棘毛虫），并对4个分类学信息不完备的已知种（冠突伪尾柱虫、新伪尾柱虫、犬牙硬膜虫、血红赭尖虫）进行细致的补充描述。这一工作，对来自不同生境腹毛类纤毛虫的多样性进行了形态学资料的补足，清理若干历史遗留的混乱，对种属间的定义进行了新的厘定和廓清，填补本领域研究的部分空白。更多还原

【Abstract】 Ciliated protozoa, which are the most complex and highly differentiated groupamong single-celled organisms, with the unique conjugation pattern and specialnuclear dualism, are important in the research fields of cell biology, development andevolution. Recently, it is one of the most active research areas of Protozoology, thatusing modern microscopic observation in vivo and silver-staining technique, toinvestigate the morphological identification of the long-term confused groups, toclarity the confusion and carry out the ontogenetic processes, and to explore thephylogenetic and evolutionary relationships among ciliated protozoa combing withmolecular data.During2007to2011, the work is including fauna survey of ciliated protozoa inthe mangrove, estuary, freshwater and soil habitats along the coasts of Yellow Sea(northern China) and South China Sea. It is mainly focused on the hypotrichousciliates (urostylids, stichotrichids and oxytrichids), which are the most complex groupin Ciliophora and significant in cell development and evolutionary phylogeny. Severalnew taxa are established, detailed redescription is carried out, unknown ontogeneticprocesses are newly investigated, new sequences data for small subunit (SSU) rRNAgene are deposited in GenBank and the secondary structures for RNA are constructed.For accurate identification among species and definition on the family and genus levelof key taxa, as well as resolution for controversial phylogenetic problems andrebuilding more reasonable system, it is providing comprehensive support informationfrom morphological, ontogenetic and molecular systematic data.The main achievements are following：1）Morphogenetic part:The twelve important, representative and significant species are selected in celldifferentiation, in taxa evolution and in phylogenetic evolution, from the unknowngroups, which own different ontogenetic patterns in three orders and six families. Thenew information during the ontogenetic processes for twelve species in nine genera(Bakuella, Metaurostylopsis, Pseudokeronopsis, Pseudourostyla, Amphisiella,Strongylidium, Rigidohymena, Rubrioxytricha and Sterkiella) is revealed and a seriesof uncertainties are clarified.Comparing and analyzing the ontogenetic characteristics among the taxa in thefamilies or sub-families, morphogenetic data are investigated as the importantsupportive references, to question the monophyly of Pseudokeronopsidae and Bakuellidae, to clarify the phylogenetic relationships among the morphologicalrelated genus of Strongylidium, and to support the establishment of Rigidohymena andits systematic position in the sub-family Stylonychinae.2）Phylogenetic and systematic part:The small subunit (SSU) rRNA gene sequences from ten genera and thirteenspecies are submitted to the GenBank for the first time. On this basis, thephylogenetic trees are constructed, the special regions in alignment are compared, andthe putative secondary structures of RNA are predicted. Using all availablemorphologic, ontogenetic and molecular data to analyze, the familyPseudokeronopsidae is redefined and the genera Thigmokeronopsis andApokeronopsis are removed out to the family Urostylidae. For the SSU rRNA genesequences for Amphisiella and Cyrtohymena from GenBank, their morphological dataare tracked and the molecular data from cryptic species are recognized.Based on the morphological, ontogenetic and molecular data of urostylid ciliatesfrom previous researches and myself, selecting characteristics from bothmorphological and ontogenetic and distinguishing the apomorph or plesiomorph ofthem, an assessment of phylogenetic relationships is given. Meanwhile, it is the firsttime to apply this particular analysis method combined with molecular phylogeneticinformation, to help rebuild new system and explore the phylogenetic relationshipamong the urostylid ciliates.3）Taxonomic part:As an additional result, one new genus（Monocoronella）and ten new species(Bakuella subtropica, Metaurostylopsis cheni, Monocoronella carnea, Monocoronelladragescoi, Pseudokeronopsis erythrina, Pseudourostyla saltans, Amphisiella pulchra,Amphisiella candida, Strongylidium orientale and Sterkiella subtropica) areestablished. And the detailed redescription for four species (Pseudourostyla cristata,Pseudourostyla nova, Rigidohymena candens and Rubrioxytricha haematoplasma) iscarried out.It supplies the biodiversity information of hypotrichous ciliates from differenthabitats, clarifies much confusion, and determines new definitions among genera andspecies.更多还原