PEET: Collaborative Research: Monographic Studies of the Hydractinioidea

9978086凯恩斯珊瑚礁是地球上最具生物多样性和生态复杂的环境之一，但我们对构成珊瑚礁和栖息在其小生境中的生物体的了解是零碎的。对于一个主要的海洋生物群体，通常与珊瑚礁有关的刺胞纲水螅虫，史密森学会的合作科学家斯蒂芬凯恩斯和杜克大学的克利福德坎宁安正在进行专题研究，同时培训水螅虫分类学方面的新专家，并汇编关于这些动物的网络访问信息数据库。根据最近的DNA序列证据，重点分类群是钟形虫科、海葵科和柱珊瑚科（或水螅），这三个形态上不同的水螅虫类群分布在世界各地，似乎构成了水生姐妹分类群。虽然淡水水螅是众所周知的，因为列文虎克的经典描述，并广泛用于现代细胞生物学研究，它是典型的缺乏水母或游泳阶段的特点，大多数海洋形式。这些形式通常有一个附着或水螅阶段以及游泳或远洋水母阶段作为生活史的一部分;在某些群体中，这两个阶段是如此不同，以至于多年来产生了不同的命名法，通常是为同一物种。这项研究的目标之一是调和这种双重分类法，部分是通过使用线粒体DNA序列作为物种相关性的标记或签名。有了一个健全的系统发育分类，关于地理分布，进化起源和多样化的克里思的问题可以有益地追求。研究人员正在与加拿大的同事（皇家安大略博物馆的戴尔·考尔德）和意大利的同事（莱切大学的费迪南德·博埃罗）以及其他人合作，研究博物馆标本，培养活生物，从实地考察中添加新材料，并培训这些生物分类学的新专家。学生将充分参与实地考察和博物馆参观，作为他们在水螅虫系统学的整体培训计划的一部分。形态学和分子证据将被整合到专题研究中，从电子显微镜的包囊和其他结构的新形态特征，和新的分子证据，从核和线粒体核糖体基因。特别是，杜克大学正在主办一个水螅虫测序设施，该设施将提供适当准备的标本的DNA序列数据，以确定水螅虫，将它们与进化亲属放在一起，并在生命周期研究中追踪水螅虫和水母阶段之间的联系。杜克大学还将主持该项目的数据库部分，纳入新的分子数据，并提供链接到Boero的12,000个分类参考和其他信息资源的电子文件。

9978086Cairns Coral reefs are among the most biologically diverse and ecologically intricate environments on earth, yet our knowledge of the organisms that constitute the reefs and inhabit their niches is fragmentary. For one major group of marine organisms often associated with reefs, the cnidarian class Hydrozoa, collaborating scientists Stephen Cairns at the Smithsonian Institution and Clifford Cunningham at Duke University are conducting monographic research while training new experts in hydrozoan taxonomy and compiling web accessible databases of information on these animals. The focal taxa are the families Campanularidae, Hydractiniidae and Stylasteridae (or hydrocorals), three morphologically distinct groups of Hydrozoa with worldwide distributions that appear to constitute phylogenetically sister taxa, on the basis of recent DNA sequence evidence. Although the freshwater Hydra is well-known since Leeuwenhoek's classic description, and is extensively used in modern cell biology research, it is atypical in lacking the medusa or swimming stage characteristic of most marine forms. These forms usually have an attached or polyp stage as well as a swimming or pelagic medusa stage as part of the life cycle; so different are the two stages in some groups that different nomenclatures have been created over the years, often for the same species. One of the goals of the research is to reconcile this dual taxonomy, in part by using mitochondrial DNA sequences as markers or signatures of species relatedness. With a sound phylogenetic classification in place, questions about biogeographic distribution, evolutionary origins, and tempo of diversification can be profitably pursued. The investigators are collaborating with colleagues in Canada (Dale Calder at the Royal Ontario Museum) and Italy (Ferdinando Boero at the University of Lecce) and others in studying museum specimens, culturing live organisms, adding new material from field expeditions, and training new experts in the taxonomy of these organisms. Students will participate fully in the field expeditions and museum visits as part of their overall training program in hydrozoan systematics. Morphological and molecular evidence will be integrated into the monographic studies, with new morphological characters from electron microscopy of nematocysts and other structures, and new molecular evidence from nuclear and mitochondrial ribosomal genes. In particular, Duke University is hosting a Hydrozoan Sequencing Facility, which will provide DNA sequence data from properly prepared collections, for purposes of identifying hydrozoans, placing them with evolutionary relatives, and tracking links between polyp and medusa stages in life cycle studies. Duke will also host the databasing component of the project, incorporating the new molecular data and providing links to Boero's electronic file of 12,000 taxonomic references and to other information resources.