Functional and Population Genomics of Ecologically Critical Eukaryotic Microbes

生态关键真核微生物的功能和种群基因组学****丛枝菌根真菌（AMF）和微孢子虫是普遍存在的影响全球生态系统功能的单细胞生物。****AMF是许多植物的根共生体，它们在土壤中的存在通常与植物适应性和生态系统生物多样性的增加有关。最近的报告表明，并非所有AMF个体（即单个孢子）都以相同的方式影响植物的适应性：一些AMF个体使一株植物比其他植物生长得更好。虽然植物生长中这种变异的原因目前尚不清楚，但有许多理由相信它们可能有遗传起源。我提出的研究的第一个目标将通过调查存在于模型AMF的单个孢子内和之间的多态性的程度和性质来解决AMF生物学的这个未知方面；Rhizophagus irregularis。这将通过将尖端的DNA测序和生物信息学技术与针对我们目前在实验室中培养的AMF分离株的创新实验设计相结合来实现。****微孢子虫是由细胞内寄生虫组成的门，与真菌谱系密切相关。这些生物可以感染包括人类在内的多种动物，近年来已经对它们的许多基因组进行了测序。迄今为止，这些基因组数据已经导致发现了可能被微孢子虫用来感染和滥用宿主的基因，但其中许多结果从未得到实验验证。我建议的第二个目标将是揭示在宿主细胞感染后特异性表达哪些微孢子虫基因。这将暴露出被微孢子虫寄生虫用来利用宿主的蛋白质。我们还将通过探索同一物种成员之间的基因组变异，以及通过研究这些寄生虫在其自然生态系统中的基因组多样性，来研究微孢子虫基因组多样性产生的机制。*这对于理解病原体如何产生新的遗传变异是至关重要的，这些变异可以用来入侵新的宿主或扩展到不同的地理区域。********

Functional and Population Genomics of Ecologically Critical Eukaryotic Microbes****The Arbuscular Mycorrhizal Fungi (AMF) and Microsporidians are ubiquitous unicellular organisms that impact the function of global ecosystems.****AMF are root symbionts of many plants, and their presence in the soils is typically linked with an increase in plant fitness and ecosystem biodiversity. Recent reports have suggested that not all AMF individuals (i.e. single spores) affect the fitness of plants in the same way: some make one plant grow better than others. Although the reasons for this variability in plant growth are presently unknown, there are many reasons to believe that they could have a genetic origin. The first objective of my proposed research will to tackle this unknown aspect of AMF biology by investigating the extent and nature of polymorphism that exists within and among individual spores of a model AMF; Rhizophagus irregularis. This will be done by combining cutting-edge DNA sequencing and bioinformatics techniques with innovative experimental designs targeted at AMF isolates that we currently grow in the lab.****The Microsporidia is a phylum composed of intracellular parasites that are closely related to fungal lineages. These organisms can infect a wide range of animals, including humans, and many of their genomes have been sequenced in recent years. To date, this genome data has resulted in the discovery of genes potentially used by microsporidians to infect and abuse their hosts, but many of these results have never been experimentally validated. The second objective of my proposal will aim to reveal which microsporidian genes are specifically expressed following infection of the host cells. This will expose the proteins that are used by microsporidian parasites to exploit their hosts. We will also investigate the mechanisms involved in the creation of genomic diversity in microsporidia by exploring genome variation among members of the same species, and by studying the genome diversity of these parasites in their natural ecosystems.*This is essential for understanding how pathogens create new genetic variation that could be used to invade new hosts or expand to different geographic areas.********