Genetics of fungal persistence and pathogenicity in mammalian hosts

项目摘要 真菌感染可能危及生命，难以治疗。 使真菌能够在人类中持续存在的遗传和分子机制可能具有重大意义。 对社会的健康益处，甚至可能使发展更有效的 抗真菌治疗模式生物酿酒酵母本身是一种机会主义的 人类病原体，有许多菌株分离自临床感染。感染的能力 在人类中持续存在，在S中并不普遍。酿酒酵母菌株。临床S.酿酒酵母 分离物往往是高度杂合的二倍体，可以在较高的温度下生长， 侵入表面。然而，严格的遗传解剖S。啤酒厂的持久性和 需要在哺乳动物宿主内的致病性。为了开始这样的工作，我们使用染色体- 编码的条形码和谱系追踪以表型一组基因分型的单倍体后代 从小鼠的酵母菌杂交中获得的。所用的特定杂交是在一个单倍体 临床分离株和参考菌株的衍生物。连锁图谱确定了几十个位点 影响真菌在哺乳动物宿主中的持久性，其中许多缺乏以前确定的 候选基因，并显示宿主器官依赖性效应。在我们的工作之后，主要问题 仍然没有答案，包括遗传，分子和生理机制， 酵母持久性和酵母-宿主相互作用;致病基因座上的等位基因如何塑造表型 与临床分离株相似的高度杂合二倍体;表面附着和 入侵的持久性和致病性;以及是否因果基因座的影响，有助于 真菌致病性具有依赖于宿主基因型的影响。在这里，我们将把我们的工作 （1）通过克隆致病菌，研究导致酵母在特定器官中持久存在的机制， 酵母中的基因，以及使用尖端显微镜和RNA-seq分析酵母宿主 （2）检测致病性等位基因的组合如何在高致病性等位基因中联合收割机组合。 杂合二倍体酵母菌株;（3）分析如何附着和侵入的能力， 表面对杂交后代致病性的影响;（4）真菌的遗传学研究 在遗传上不同的小鼠宿主中的致病性。我们的建议将利用尚未开发的 芽殖酵母模型系统的潜力，以提供具体的遗传学和 机会致病真菌致病性的分子机制。

Project Summary Opportunistic fungal infections can be life-threatening and difficult to treat. Identifying the genetic and molecular mechanisms that enable fungi to persist in humans could have major health benefits for society, potentially even enabling the development of more effective antifungal therapies. The model organism Saccharomyces cerevisiae is itself an opportunistic human pathogen, with many strains isolated from clinical infections. The ability to infect and persist within humans is not universal among S. cerevisiae strains. Clinical S. cerevisiae isolates tend to be highly heterozygous diploids that can grow at higher temperatures and invade into surfaces. However, rigorous genetic dissection of S. cerevisiae’s persistence and pathogenicity within mammalian hosts is needed. To begin such work, we used chromosomally- encoded barcodes and lineage tracking to phenotype a panel of genotyped haploid progeny from a budding yeast cross in mice. The specific cross employed was between a haploid derivative of a clinical isolate and the reference strain. Linkage mapping identified dozens of loci influencing fungal persistence within a mammalian host, many of which lack previously identified candidate genes and show host organ-dependent effects. Following our work, major questions remain unanswered, including the genetic, molecular, and physiological mechanisms underlying yeast persistence and yeast-host interactions; how alleles at causal loci shape the phenotypes of highly heterozygous diploids resembling clinical isolates; the role of surface attachment and invasion in persistence and pathogenicity; and whether the effects of causal loci contributing to fungal pathogenicity have effects that depend on host genotype. Here, we will extend our work by (1) studying mechanisms causing yeast persistence in particular organs by cloning causal genes in yeast, as well as by using cutting-edge microscopy and RNA-seq to analyze yeast-host interactions; (2) testing how combinations of pathogenicity alleles combine in highly heterozygous diploid yeast strains; (3) analyzing how the ability to attach to and invade into surfaces influences the pathogenicity of cross progeny; and (4) examining the genetics of fungal pathogenicity across genetically distinct mouse hosts. Our proposal will utilize the untapped potential of the budding yeast model system to provide concrete insights into the genetics and molecular mechanisms underlying opportunistic fungal pathogenicity.