Collaborative Research: Testing hypotheses about diversity, gene flow, and effective population size in marine planktonic ciliates

环境微生物学的分子和经典方法的脱钩并没有取得成果，它代表了未来几年该领域最重要的挑战之一。经典的方法集中在几个世纪以来的传统，即通过细致的观察和分析来描述单个物种，以生成专著，例如为植物和动物所做的。不幸的是，对新分子技术的追求有时忽略了这一传统，声称从未见过的新谱系，以及基于环境DNA样本的微生物真核生物惊人多样性的报告，甚至没有得到最基本的显微镜观察的支持。面对传统方法与分子方法之间的脱节，本项目是海洋纤毛虫多样性和基因流研究中两种方法的结合。初步数据表明，在一些分支的亚热带纤毛虫（Strombidididae）确实有一个高水平的分子多样性的基础上相对较少的形态种。在其他分支（一些choreotrichs），相反的情况似乎是正确的，与形态异质性明显克隆线的基础上，基于分子数据。目前，我们不知道是什么维持了一些分支的多样性;我们也不知道为什么其他分支表现出低多样性。这个问题既可以用实验方法也可以用观测方法来解决。该项目将遵循双管齐下的方法，结合分子（克隆文库，DGGE，FISH）和传统（光学显微镜）技术来解决三个广泛的问题：1）。影响南极海洋纤毛虫分布和多样性的最重要的物理和生物因素是什么？2）。海洋纤毛虫种群的有效种群规模是多少，与人口普查的种群规模相比如何？3）。传统的纤毛虫形态学描述与分子生物学描述相比，表现如何？使用分子和显微镜方法相结合，研究人员将解决这些问题，在沿海浮游纤毛虫。对所得数据的分析将深入了解北大西洋内纤毛虫物种的性质和基因流动的模式，这一提议的更广泛影响包括对K-12教育工作者的培训和推广。PI有一个过去的记录，证明在培养本科生和研究生的成功。这两个PI在指导传统上代表性不足的群体的学生方面都有良好的记录，他们将继续致力于扩大该项目参与者的多样性。PI还将通过与位于康州大学的私人非营利海洋教育组织Project Oceanology的合作伙伴关系参与教师培训。该项目的每个夏天，他们将接待两名K-12教师，他们将获得学费奖学金，在PI的监督下，获得纤毛虫生物学和生态学研究经验的研究生学分。最后，将通过互联网和出版物提供该项目的结果数据。

The decoupling of molecular and classical approaches to environmental microbiology has not been fruitful and it represents one of the most important challenges for the field in the coming years. Classical approaches center on the centuries-old tradition of describing individual species via meticulous observation and analysis to generate monographs, such as is done for plants and animals. Unfortunately, the rush to new molecular techniques has sometimes ignored this tradition, with claims about new lineages never seen before and reports of staggering diversity of microbial eukaryotes based on environmental DNA samples not backed up by even the most elementary microscopic observations. In the face of this disconnect between the traditional and the molecular, this project is a marriage of the two approaches in the study of marine ciliate diversity and gene flow. Preliminary data show that in some clades of planktonic ciliates (Strombidiidae) there is indeed a high level of molecular diversity underlying a relatively small number of morphospecies. In other clades (some choreotrichs), the opposite appears to be true, with morphological heterogeneity underlain by apparently clonal lines, based on molecular data. Currently, we do not understand what sustains diversity in some clades; nor do we know why other clades show low diversity. This problem is amenable to both experimental and observational approaches. This project will follow a two-pronged approach, combining molecular (clone libraries, DGGE, FISH) and traditional (light microscopy) techniques to address three broad questions: 1). What are the most important physical and biological factors that affect distribution and diversity of planktonic marine ciliates? 2). What is the effective population size for marine ciliate populations, and how does this compare to census population sizes? 3). How well do traditional morphological descriptions of ciliate species fare when compared with molecular characterizations? Using a combination of molecular and microscopy methods, the investigators will address these questions in coastal planktonic ciliates. Analyses of the resulting data will yield insights into the nature of ciliate species and patterns of gene flow within the North Atlantic.The broader impacts of this proposal include training and outreach to K-12 educators. The PIs have a past record that demonstrates success in training both undergraduate and graduate students. Both PIs have proven track records in mentoring students from traditionally underrepresented groups, and they will continue to aim recruitment activities towards broadening diversity of participants in this project. The PIs will also participate in teacher training through a partnership with Project Oceanology, a private non-profit marine education organization located at UConn. Each summer of the project they will host two K-12 teachers who will receive tuition scholarships to earn graduate credit for research experiences in ciliate biology and ecology under the supervision of the PIs. Finally, resulting data from this project will be made available through the internet as well as in publications.