寡毛类水丝蚓属的分类学修订

Although there are many the ecological surveys, and physiological and toxicological studies of polluted or even toxic matters on the sludge worm Limnodrilus worms, the systematics of Limnodrilus (Annelida: Clitellta: Naididae) is relatively not well studied. Traditional taxonomic classification of Limnodrilus is based on a limited morphologic criteria，this classification does not take into account genetic and other evidence. However, morphological identification of Limnodrilus species is a well-known challenge, since it is not unusual to encounter forms that are representatives of previously known great morphological variability within Limnodrilus species, especially, from different regions. Taxonomic revision of Limnodrilus, as well as fauna survey for this genus, are in urgent need of further systematic studies, which it is critical to combine, at least, morphological study with phylogenetic analysis. The aim of this project is to revise the status of all Limnodrilus species from types or topotype specimens from the world's natural history collections, which allowed the candidate to propose emendations and description for newly found unknown species with proper binomial names, and provide qualified illustrations, as well as genetic evidence. The updated systematics of Limnodrilus is likely contributed to our understanding of the evolutionary relationships within the family Naididae, and it also shed light on the classification of some genera with a similar controversial taxonomic issue. In addition, based on a sizable genetic reference dataset generated from taxonomically validated Limnodrilus specimens, Mata-barcoding will help facilitate the rapid biodiversity assessments and biomonitoring, especially in in eutrophic water bodies.

隶属环节动物门仙女虫科水丝蚓属的部分物种为污染水体中最常见优势类群，与该属相关的生理学、生态学和毒理学研究非常多，但是该属的分子系统学和分类研究相对滞后。经典分类学研究侧重从相对少量的形态特征角度区别近源物种，有限的研究人力和物力无法兼顾种内不同群体间的形态变异信息，如不同地区种群之间的差异。对世界范围内的水丝蚓属类群厘定和国内区域性系统分类学研究尚待整合形态和分子数据来实现。本项课题拟通过中外协力合作，研究比较地模标本和已有的模式标本，对水丝蚓属进行系统的形态比较和分子系统学研究，厘订世界水丝蚓属种类及描述尚未命名的物种，并提供相应的分子数据和形态数据。该研究结果为下一步开展仙女虫科及其属间的系统与进化，和分类修订提供基础资料。此外，定名水丝蚓物种的分子数据也有助于利用复合条形码技术进行生物多样性快速评估和环境监测方面，尤其是在水丝蚓为优势种的富营养化的水生环境，具有十分重要的实践意义。

寡毛类中药材在我国有着悠久的临床使用经验史，中药材质量与药材基原物种的遗传多样化、化学成分多样性、生态系统多样息息相关，其中物种准确性是保障中药质量的关键。《中华人民共和国药典》2020版收录的药用水蛭为环节动物门黄蛭科动物宽体金线蛭Whitmania pigra Whitman（俗称：蚂蟥）、日本医蛭Hirudo nipponica Whitman（俗称：水蛭）和尖细金线蛭Whitmania acranulata, Whitman（俗称：柳叶蚂蟥）的干燥全体。在不同的蛭类中提取的具有抗凝血的活性成分主要为蛋白质和各种多肽类大分子物质，但活性成分的分子大小和构象及作用机理却不尽相同依据传统形态特征难以鉴定来源复杂的药用寡毛物种，药用蛭通常需经过炮制等过程制成干体或者炮制品出售，这也大大增加了利用传统方法鉴定蛭类的难度。此外，国内寡毛生物多样性和系统发育关系缺乏相对系统的研究，严重制约该类中药资源的精准开发和利用。在徐州地区采集了药典收录的宽体金线蛭、尖细金线蛭、日本医蛭和光润金线蛭四种野生蛭类，获得了四种蛭类的线粒体基因组和简化基因组。1）依据徐州附近同一地点的采集光润金线制标本外表形态多样，基于12S、16S、ND1、COX1基因设计的DNA微型条形码引物扩增效率明显高于标准条形码的引物，已经成功在8种市售蛭类制品的中成药中扩增检测到药品所用蛭类的目的DNA片段，这为检测药用蛭类的规范化使用提供了技术支持。2）利用线粒体基因组及和核基因数据构建了常用药用金线蛭属及其公共数据库中相关序列的系统发育树，确认了吸血蛭类日本医蛭与非吸血蛭类金线蛭属有较近的亲缘关系的事实，也从一个方面证实了金线蛭属药用价值，此外对GenBank数据库中部分已经上传的序列的物种存在鉴定错误或测序污染序列进行了甄别。3）在后续研究中依据补充的标本进一步挖掘非吸血蛭类的起源及其活性成分的挖掘。

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