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

环境微生物学分子与经典方法的解耦尚未取得丰硕成果，这是未来几年该领域面临的最重要挑战之一。经典的方法集中在几个世纪以来的传统上，通过细致的观察和分析来描述单个物种，从而产生专著，就像对植物和动物所做的那样。不幸的是，对新分子技术的狂热有时忽视了这一传统，关于新谱系的主张从未见过，以及基于环境DNA样本的微生物真核生物惊人多样性的报道，甚至没有最基本的显微镜观察的支持。面对传统和分子之间的脱节，本项目是海洋纤毛虫多样性和基因流研究两种方法的结合。初步数据表明，在浮游纤毛虫的一些分支中，在相对较少的形态物种的基础上，确实存在着高水平的分子多样性。在其他进化支（一些舞蹈生物）中，情况似乎正好相反，根据分子数据，形态异质性由明显的克隆系支撑。目前，我们不知道是什么维持了一些进化枝的多样性；我们也不知道为什么其他进化支表现出低多样性。这个问题可以用实验和观察两种方法来解决。该项目将采用双管齐下的方法，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)。影响浮游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)。与分子表征相比，传统的纤毛虫形态描述如何？利用分子和显微镜相结合的方法，研究人员将在沿海浮游纤毛虫中解决这些问题。对结果数据的分析将有助于深入了解纤毛虫物种的性质和北大西洋内基因流动的模式。该提案的更广泛影响包括对K-12教育工作者的培训和推广。pi过去在培养本科生和研究生方面都有成功的记录。这两家学院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项目参与者的多样性。这些pi还将通过与位于康涅狄格大学的私人非营利性海洋教育组织“海洋项目”（Project Oceanology）合作，参与教师培训。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，以获得研究生学分，在pi的监督下进行纤毛虫生物学和生态学的研究经验。最后，该项目的结果数据将通过互联网和出版物提供。

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.