黄海沿岸底栖纤毛虫主要类群的分类和系统发育研究

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	黄海沿岸底栖纤毛虫主要类群的分类和系统发育研究
	李菊
学位类型	博士
导师	徐奎栋
	2016
学位授予单位	中国科学院大学
学位授予地点	北京
学位专业	海洋生物学
关键词	底栖纤毛虫形态学系统发育黄海
摘要	在海洋底栖环境中，以纤毛虫为代表的原生动物在海洋底栖微食物网的物质循环与能量流动过程中，发挥着不可或缺的作用。复杂多变的海洋底栖环境，为多种多样的纤毛虫栖息提供了不同生境，已有研究表明，底栖纤毛虫无论是在丰度还是多样性上都明显高于水体种类，然而由于采样量的不足和鉴定错误，海洋底栖纤毛虫仅有小部分物种被正确报道。于2012年7月至2015年10月，对采自山东青岛、威海和江苏盐城等地的潮间带、河口等生境的纤毛虫展开了形态学和分子生物学研究。通过活体观察与蛋白银染色相结合的方法，对纤毛虫的活体形态和纤毛图式进行了细致的研究，对误鉴定种和鉴别困难种进行了重描述；通过SSU rRNA，ITS1-5.8S-ITS2，LSU-rRNA基因测序、序列对比、预测二级结构，构建系统发育树等方法进行系统发育研究。主要成果包括形态学和分子系统学两个部分。在形态学方面，详细描述了广义腹毛类(腹毛亚纲、游仆亚纲)、异毛纲和管口亚纲的20属30种纤毛虫，主要包括： 1. 结合活体形态和纤毛图式等形态学信息和核糖体小亚基基因序列，通过与相近种比较，发现并描述3个新种：海洋尾全列虫Caudiholosticha marina n. sp.，念珠尾全列虫Caudiholosticha monilata n. sp. 和黄色假列虫Nothoholosticha flava n .sp. 2. 基于青岛种群，对拟红色伪角毛虫Pseudokeronopsis pararubra Hu et al., 2004，肉色伪角毛虫P. carnea (Cohn, 1866) Wirnsberger et al., 1987，红色伪角毛虫P. rubra (Ehrenberg, 1836) Borror & Wicklow, 1983和相似拟双棘虫Parabirojimia similis Hu et al., 2002进行了细致的补充描述；确定拟红色伪角毛虫为有效命名并对伪角毛虫所有种进行了形态比较。 3. 报道多毛异列虫Anteholosticha multicirrata Park et al., 2013，长尖毛虫Oxytricha longa Gelei & Szabados, 1950和汤氏棘毛虫Sterkiella thompsoni Foissner, 1996三个中国新纪录种，并对长尖毛虫和汤氏棘毛虫进行了细致的补充描述。在分子系统学方面，对19属45种纤毛虫进行了测序分析，新增加了45条SSU rDNA，22条ITS1-5.8S-ITS2区域，21条LSU-rDNA序列。通过序列对比、预测二级结构、构建系统发育树，并结合形态学信息、细胞发生学信息，对腹毛亚纲、异毛纲和管口亚纲内部系统发育关系进行了系统的分析。主要成果包括： 1. 在腹毛亚纲中，由于ITS1-5.8S-ITS2区序列具有明显的遗传距离间隔，可作为伪角毛虫属Pseudokeronopsis种间区分的分子标记，ITS2二级结构信息也可以辅助区分相近种；对GenBank中的伪角毛虫序列进行了清理，去除或转移鉴定错误的序列；基于核糖体小亚基基因的系统发育分析，进一步证明了尾全列虫属Caudiholosticha为多源发生，确定了假列虫属Nothoholosticha的系统学地位，提出额前棘毛的有无可能并非假列虫亚科Nothoholostichinae内属间区分的重要特征。 2. 基于核糖体小亚基基因构建的系统发育树显示，异毛纲中的突口虫属Condylostoma的单源发生性未得到支持，但由于模式种分子信息的缺失，其是否为单系群仍有待进更多信息证实。 3. 管口亚纲中的偏体虫科Dysteriidae、哈特曼虫科Hartmannulidae、齿管虫科Chlamydodontidae和斜管虫科Chilodonellidae均表现出单源发生；偏体目Dysteriida为单源发生，但齿管目Chlamydodontida的单源发生未得到支持。
其他摘要	Marine microbenthos, represented by ciliated protozoa, are important components in the process of material recycle and energy flow in benthic microbial food webs. Because of the complexity and diversity of marine benthic environment, multiple kinds of habitats exist for various ciliates. Previous research has shown that benthic ciliates have higher diversity and abundance than planktonic ones. Nevertheless, due to the undersampling and misidentification, only a small part of benthic ciliates were reported. This work includes morphological and molecular data of ciliates sampled from from different habitats, such as beaches, reefs, estuaries and docks in Qingdao, Yancheng, Dongying, Weihai and other regions in the Yellow Sea during July 2012 to October 2015. Live observation and protargol impregnation were used to reveal the living features and ciliary pattern. Improves diagnosis are provided for misidentified species and ones with confusing morphological feature. SSU rRNA，ITS1-5.8S-ITS2，LSU-rRNA gene were sequenced for sequence alignment, secondary structure prediction and construction of phylogenetic trees for phylogenetic analyses. Main results include morphology and molecular phylogeny: In the morphological part, 30 species of 20 genera, belonging to Hypotrichia, Heterotricha and Cyrtophoria are described in detail, which include: 1. Establishment of 3 new species Caudiholosticha marina n. sp., Caudiholosticha monilata n. sp. and Nothoholosticha flava n. sp. are established based on morphological and SSU rDNA information. 2. Redescription of 3 species and reestablishment of one species Re-establishment of Pseudokeronopsis pararubra Hu et al., 2004 is conducted based on the population isolated from Qingdao. Invastigate and improved diagnosis of P. carnea (Cohn, 1866) Wirnsberger et al., 1987， P. rubra (Ehrenberg, 1836) Borror & Wicklow, 1983 and Parabirojimia similis Hu et al., 2002 are provided, together with systematic review of Pseudokeronopsis. 3. Records of 3 species Anteholosticha multicirrata Park et al., 2013, Oxytricha longa Gelei & Szabados, 1950 and Sterkiella thompsoni Foissner, 1996 were first found in China with morphological information based on living observation and infraciliature. In the molecular phylogenetic part, 45 species of 19 genera were sequenced and 45 SSU rDNA, 22 ITS1-5.8S-ITS2 region and 22 LSU-rDNA sequences were added. Sequence alignment, secondary structure prediction and construction of phylogenetic trees were conducted for phylogenetic analyses. The results are following: 1. In the Hypotrichia, ITS1-5.8S-ITS2 region sequences poccess obvious divergent distance gap to discriminate close species in Pseudokeronopsis with the second structure of ITS2 as assistant. Pseudokeronopsis sequences in GenBank were revised with transferring and removing of sequences of misidentified species. Phylogentic analyses based on SSU rDNA sequences supports the polygeny of Caudiholosticha and the systematic status of Nothoholosticha with hypothesis that presence or absence of frontoterminal cirri is not a key feature to distinguish genera of the subfamily Nothoholostichinae. 2. Phylogenetic analyses with adding SSU rRNA gene sequences of four Condylostoma species rejected monophyly of Condylostoma, but its monophyly need more molecular information especially that of the type species. 3. Monophyly of Dysteriidae, Hartmannulidae, Chlamydodontidae and Chilodonellidae in Cyrtophoria was supported and monophyly of Chlamydodontida was rejected by phylogenetic analyses with adding SSU rDNA sequences of six species.
学科领域	生物学
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/112558
专题	海洋生物标本馆
作者单位	中国科学院海洋研究所
推荐引用方式 GB/T 7714	李菊. 黄海沿岸底栖纤毛虫主要类群的分类和系统发育研究[D]. 北京. 中国科学院大学,2016.

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