Quantitative genetic approaches to Candida albicans oropharyngeal pathogenesis

摘要： 白色念珠菌是一种多态性酵母菌，也表现为一种普遍的机会致病菌。 真菌病原体C.白色念珠菌感染表现为口咽念珠菌病（OPC）或鹅口疮， 免疫力低下的人。在这里，我们部署数量性状基因座（QTL）分析来识别基因 负责不同形式的口腔疾病，并剖析管理致病性 在C.白色念珠菌这些实验将为所有人开发定量遗传方法。 拟性假丝酵母属。 C.白色念珠菌在菌株之间具有显著的表型多样性，并且能够稳定地存在于 口腔或诱导上皮损伤，导致免疫系统或OPC清除。然而，在这方面， 控制菌株之间这些疾病表型差异的遗传基因座尚不清楚。到 为了解决这一问题，将两个分离物529L和SC5314（分别为稳定的定殖者和破坏者）交配， 产生准有性后代。后代基因组在标记位置进行测序，覆盖约1%的 基因组高重组率在parasex促进19个QTL区域的定位与 使用铬释放测定的上皮损伤表型。目标1将测试特定的位点，从这些 用于鉴定损伤和免疫系统清除或非损伤的遗传决定因素的QTL 持久性，区分菌株。此外，将进行菌丝形成的QTL分析， 形成和宿主细胞损伤在一些后代中是可分离的表型。 C.白色念珠菌利用趋化作用破坏上皮表面， 感染目前的执行模式并没有考虑到执行中的实质性差异， C.白色念珠菌分离株。为了确定物种范围内的调节子，我们将采用QTL技术， Aim 2中4株具有不同的表型。来自所有成对交配的QTL将揭示基因 当在30 ℃下在三种不同的诱导培养基上生长时调节表达表型的差异， 37 ℃，以模拟人类宿主的口腔和内部体温。成丝表型将 用一种新的高通量视觉分析程序进行评分。因此，定量遗传学的建立 在准有性种中的方法将大大提高C.白色念珠菌致病调节因子。 作为一名研究生，我的目标是成为一名科学家，其研究汇集了多种科学 学科在追求这些目标的同时，我将发展我在板凳上和计算机上的技能， 信息学和生物学之间的差距，在科学中的作用越来越重要。在整个项目中，我将 通过向本地和国际科学观众展示这项工作来发展我的沟通技巧， 与其他科学家合作，撰写我的作品，以便向科学界和外行更广泛地传播 社区.

Abstract: Candida albicans is a polymorphic commensal yeast that also manifests as a prevalent opportunistic fungal pathogen. C. albicans infections manifest as oropharyngeal candidiasis (OPC), or thrush, in immunocompromised individuals. Here, we deploy quantitative trait loci (QTL) analysis to identify genes responsible for different forms of oral disease and to dissect regulatory networks governing the pathogenic process of filamentation in C. albicans. These experiments will develop quantitative genetic approaches for all parasexual Candida species. C. albicans has substantial phenotypic diversity among strains and is capable of residing stably in the oral cavity or inducing epithelial damage that leads to either clearance by the immune system or OPC. However, the genetic loci governing differences in these disease phenotypes between strains are not understood. To address this, two isolates 529L and SC5314, a stable colonizer and damager, respectively, were mated to generate parasexual progeny. Progeny genomes were sequenced at marker positions covering ~1% of the genome. High rates of recombination during parasex facilitated mapping of 19 QTL regions associated with epithelial damage phenotypes using a chromium release assay. Aim 1 will test specific loci from within those QTLs to identify genetic determinants of damage and clearance by the immune system or non-damaging persistence that differentiate strains. Furthermore, QTL analysis of filamentation will be performed, as hyphal formation and host cell damage were separable phenotypes in some progeny. C. albicans uses filamentation to disrupt epithelial surfaces and progress into a disseminated systemic infection. Current models of filamentation do not account for the substantial differences in filamentation among C. albicans isolates. To identify species-wide regulators of filamentation, we will employ QTL techniques using 4 strains with distinct filamentation phenotypes in Aim 2. QTLs from all pairwise matings will uncover genes regulating differences in filamentation phenotypes when grown on three different induction media at 30oC and 37oC to mimic the oral cavity and internal body temperature of the human host. Filamentation phenotyping will be scored with a novel high-throughput visual analysis procedure. Thus, establishment of quantitative genetic approaches in a parasexual species will greatly enhance identification of C. albicans pathogenesis regulators. My goal as a graduate student is to become a scientist whose research brings together multiple scientific disciplines. While pursuing these aims, I will develop my skills at the bench and at the computer to bridge the gap between informatics and biology, an increasingly important role in science. Throughout this project, I will develop my communication skills by presenting this work to scientific audiences locally and internationally, collaborating with other scientists, and writing my work for broader dissemination to the scientific and lay communities.