Labyrinthulomycete diversity and abundance

实验室的thulomycetes（naturalthulids，thraustochytrids和aplanochytrids）是普遍存在的，多样的，丰富的海洋原生生物。它们被认为主要作为saprobes生活，从藻类，高等植物或动物来源的非生命颗粒有机物（POM）中获得营养。因此，虽然在分类学意义上，Labelothulomycetes不是“真菌”，但在生态学意义上，它们可能具有“真菌”的功能，在POM的分解中发挥类似的作用。由于其高含量的必需多不饱和脂肪酸（PUFAs），Labelothulomycetes也可能通过改善碎屑的食物质量（“营养升级”）在海洋后生动物的营养中发挥作用。然而，他们的作用分解海洋POM的证据是有点间接的，因此不支持定量的结论，他们的功能或重要性。该项目的长期目标是收集有关Labelihulomycete丰度和多样性的证据，以便更好地了解它们在海洋生态系统中的作用。该项目旨在开发基于聚合酶链反应（PCR）的分子遗传学方法，以调查Labelihulomycete的多样性和丰度。现有的18 S核糖体DNA（rDNA）的实验室-thulomycete特异性PCR引物不能识别实验室-thulomycete多样性的一个潜在的重要组成部分（一些组的破囊壶菌）。研究人员将开发新的18 S rDNA引物，以便更好地估计Labelihulomycetes的多样性，然后使用这些引物从各种栖息地收集18 S rDNA序列数据。所得到的序列数据将相对于当前培养物中的代表性在田间量化这些生物体的多样性。这些引物（或在项目过程中设计的其他引物）将用于开发定量实时PCR分析，以确定环境样本中Labelothulomycetes（和Labelothulomycetes亚群）的丰度。更广泛的影响：正如对异养细菌重要性的认识彻底改变了我们对浮游生物食物网的理解一样，对Labelothulomycetes进行更全面的调查可能会改变我们对POM在海洋中的命运及其与后生动物食物网的联系的理解。两名本科生将继续参与该项目，从事分子遗传学方面的工作（协助PCR，克隆和测序）和培养工作。参与研究斯托尼布鲁克大学（SBU）的多元化学生团体提供了一个机会，以增加在科学代表性不足的群体的存在。已经在从事这个项目的研究生也是一个代表性不足的群体的成员。一个或两个高中生将在实验室工作，每年夏天在这个项目上工作; SBU和PI都有很好的记录，主办当地高中学生赞助的学生-教师研究合作。

The Labyrinthulomycetes (labyrinthulids, thraustochytrids, and aplanochytrids) are ubiquitous, diverse, and abundant marine protists. They are thought to live mainly as saprobes, obtaining their nutrition from non-living particulate organic matter (POM) of algal, higher plant, or animal origin. Thus, while Labyrinthulomycetes are not "fungi" in a taxonomic sense, they may function as "fungi" in an ecological sense, playing similar roles in the decomposition of POM. Because of their high content of essential polyunsaturated fatty acids (PUFAs), Labyrinthulomycetes may also play a role in the nutrition of marine metazoans by improving the food quality of detritus ("trophic upgrading"). However, evidence of their role decomposing marine POM is somewhat circumstantial, and thus does not support quantitative conclusions about their function or importance. The long-term goal of this project is to gather the evidence about Labyrinthulomycete abundance and diversity that will be needed to better understand their role in marine ecosystems.This project aims to develop molecular genetic methods based on the polymerase chain reaction (PCR) to investigate the diversity and abundance of Labyrinthulomycetes. The existing Labyrinthulomycete-specific PCR primers for 18S ribosomal DNA (rDNA) cannot recognize a potentially important component of Labyrinthulomycete diversity (some groups of thraustochytrids). The investigators will develop new 18S rDNA primers that will allow better estimation of the diversity of the Labyrinthulomycetes, and then use these primers to gather 18S rDNA sequence data from a variety of habitats. The resulting sequence data will diversity of these organisms to be quantified in the field relative to the representatives currently in culture. These primers (or others designed in the course of the project) will be used to develop quantitative real-time PCR assays to determine the abundance of Labyrinthulomycetes (and subgroups of Labyrinthulomycetes) in environmental samples. Methods will also be developed to cultivate novel Labyrinthulomycetes detected in local sediments during the preliminary sequencing efforts.BROADER IMPACTS: Just as the recognition of the importance of heterotrophic bacteria revolutionized our understanding of planktonic food webs, more complete investigation of the Labyrinthulomycetes could change our understanding of the fate of POM in the oceans and its linkage to metazoan food webs. Two undergraduates will be continuously involved in this project, working on both the molecular genetic aspects (assisting with PCR, cloning, and sequencing) and on the culturing efforts. Involving the diverse student body of Stony Brook University (SBU) in research provides an opportunity to increase the presence of underrepresented groups in the sciences. The graduate student already working on this project is also a member of an underrepresented group. One or two high school students will work in the lab each summer working on this project; both SBU and the PI have strong track records of hosting local high school students for sponsored student-faculty research collaborations.