排毛目纤毛虫原生动物的细胞发生模式比较和系统发育关系构建

Ciliates are the highest group in protozoa and have the most complex and differentiated organelles and important evolutionary position, as well as show a higher diversity of species. Stichotrichida, a key taxa with most important special evolutionary and developmental position. Hence, the investigation of its morphogenesis or cell development, which concerns the pattern formation of cortical structures on/beneath cell surface during binary division are always extremely interesting for researchers engaged in cell differentiation, systematics as well as evolution because morphogenesis of these organisms play an important role both in deducing phylogenetic relationships and to outline/separate closely related groups. More important, the pattern features of cortical structures (e.g. the origin ways of oral primordium, developing forms of cirral as well as other ciliature organelles etc.) appeared during the division process indicate essential mechanisms of systematics and evolution of "protozoa". The current project will study about 30 important forms which are living in Qinling Mountain, concerning their ontogenesis, developing mode of cortical structures and pattern formation using the "modern" methods and obtain the molecular information of about 80 significant or representative species/populations, mainly focused on SS rRNA, ITS1-5.8S-ITS2, alpha-tubulin genes sequences. Based on the combination of morphological, morphogenetical, multi-gene sequencing and phylogenetic information, the project will be performed i) to investigate the morphogenetic process during asexual fission of species/taxon which are un- / poorly-known or mean much to evolution, cell differentiation and system evolvement. Based on the analysis on these results and comparing the diversity of their pattern information, to present and outline the division modes of these taxon and systematic relationship among Amphisiellidae, Epiclintidae, Kahliellidae, Spirofilidae, Strongylidae and Psilotrichidae; ii) to discuss and analyse the phylogeny of about 12 most important and most confused groups at order/family/genera level; iii) to re-/evaluate the systematic relationship and phylogenetic position between/among the taxa which the species are traditionally arranged in.

纤毛门原生动物为分化最高等的单细胞真核动物，具有特殊的进化地位，排毛目是腹毛门中具有非常关键和特殊的系统发育地位的阶元，探讨其个体发育与系统进化是国际原生动物学领域当今的研究难点与热点之一。本研究拟以秦岭地区多种土壤和气候生境中分布的排毛目纤毛虫为研究对象，研究具有代表性和系统重要地位的种类在个体发育中的起源、演化和细胞器的起源、分化、结构的近祖衍生分析等内容，探讨未知类群的发育模式。同时扩充和构建亟待研究类群的纤毛虫基因库，完成对约80种的SS rRNA，ITS1-5.8S-ITS2，alpha-tubulin基因测序、提交及建库。在整合形态学、发生模式及多重分子标记探讨的基础上，解决排毛目内部的系统待解决/争议性问题，构建排毛目科-目级类群的新系统及深入探讨和精确构建排毛目与尾柱目和散毛目进化发育演化关系。为"原生动物"这一多源体系的起源与演化探讨提供重要的基础资料。

纤毛虫为最高等和结构最复杂的一大类原生动物，而腹毛类则是纤毛虫中特化程度最高的类群，其物种和发生模式高度多样，是当今国际纤毛虫学的热点研究领域之一。对排毛目不同发生型的具有重要类群进化、系统演化意义的关键种之无性繁殖过程中的细胞发生学研究，涉及了不同类群的起源、演化、重要胞器结构的近祖-衍化模式建立等；发现和报道了大量新现象；建立并界定了13个属种的细胞发生模式及所代表类群的系统地位。对排毛目中的6个科级类群内/间系统关系的修订、皮膜演化趋势的探讨；对重要类群的标记性基因测序、分析；代表性科目级类群间分子系统关系的探讨建立，具体涉及：确定了伪瘦尾虫属和圆纤虫属之间相近的亲缘关系；揭示了列毛虫为伪尾柱虫科和伪角毛虫科的居间类群；确立拟枝毛虫属为枝毛虫属与施氏毛虫属之间的过渡类群，拟枝毛虫属为与施氏毛虫属具最近亲缘关系的类群；揭示了尾柱虫属与伪尾柱虫属的发生方式并无缘棘毛原基发育方面的不同，淡化了该特征在系统研究方面的权重，澄清了前人对该科在系统进化中所表现的相关趋同现象的错误理解；将具18根额腹横棘毛的广义的尖毛虫各属进行了系统的清理和修订，廓清了各属的定义，给出了各个属的特征模式图和总检索表，并对各类群的形态和发生学模式进行了总结和比较；对瘦尾虫属内所有物种进行了定义的廓清，特征的明确，种内的清理和修订，种间区别的划分；将尾全列虫属挪入瘦尾虫科下的瘦尾虫属内，作为该属下的一个新亚属，将尾全列虫属里其他属从该属中提取出来，归入其他属内。利用现代技术完成了对十余种“纤毛图式”研究、形态学重描述，填补了上述类群分类学中长期存在的、现代分类信息的缺失和大量空白点。建立了新的高阶阶元：1个新属拟枝毛虫属和9个新种，对11个已知种类进行了重要的重描述。构建了含88个物种的DNA库，并将36个序列向Genbank提交。累计形成和发表研究论文16篇，均为SCI-收录刊物，15篇为第一标注。