Labyrinthulomycete diversity and abundance

迷路真菌(迷路类、鞭毛类和无尾类)是普遍存在的、种类繁多且数量丰富的海洋原生动物。它们被认为主要作为腐殖体生活，从藻类、高等植物或动物来源的非生物颗粒有机物(POM)中获取营养。因此，虽然迷宫真菌不是分类学意义上的“真菌”，但它们可能在生态学意义上起到“真菌”的作用，在POM的分解过程中扮演着类似的角色。由于迷宫菌含有高含量的必需多不饱和脂肪酸(PUFAs)，它们还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，它们分解海洋POM的作用的证据在某种程度上是间接的，因此不支持关于它们的功能或重要性的定量结论。该项目的长期目标是收集有关迷路真菌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式反应(PCR)的分子遗传学方法来调查迷路真菌的多样性和丰度。现有的18S核糖体DNA(RDNA)迷路真菌特异的聚合酶链式反应(18S RDNA)引物不能识别迷路真菌多样性的一个潜在的重要组成部分(一些类群)。研究人员将开发新的18S rDNA引物，以便更好地估计迷宫真菌的多样性，然后使用这些引物从各种栖息地收集18S rDNA序列数据。由此产生的序列数据将使这些微生物的多样性在现场相对于目前培养中的代表进行量化。这些(或在项目过程中设计的其他)引物将用于开发实时定量聚合酶链式反应分析，以确定环境样品中迷路真菌(和迷路真菌亚群)的丰度。在初步测序工作中，还将开发培养在当地沉积物中发现的新型迷宫真菌的方法。BROADER影响：就像对异养细菌重要性的认识彻底改变了我们对浮游食物网的理解一样，对迷宫菌进行更全面的研究可能会改变我们对海洋中POM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这个项目，从事分子遗传学方面的工作(协助聚合酶链式反应、克隆和测序)和培养工作。让石溪大学(SBU)多样化的学生群体参与研究，为增加科学界代表性不足的群体提供了机会。已经在这个项目上工作的研究生也是一个代表性不足的群体的成员。每年夏天都会有一到两名高中生在实验室从事这一项目；SBU和PI在接待当地高中生进行受赞助的师生研究合作方面都有很好的记录。

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.