Quantitative genetic approaches to Candida albicans oropharyngeal pathogenesis

摘要： 白色念珠菌是一种多态的共生酵母，也表现为一种普遍的机会主义。 真菌病原体。白色念珠菌感染表现为口咽念珠菌病(OPC)，或鹅口疮 免疫功能受损的个体。在这里，我们采用数量性状基因座(QTL)分析来识别基因 负责不同形式的口腔疾病，并剖析管理致病因素的监管网络 白色念珠菌的丝状化过程。这些实验将为所有人开发定量遗传方法 异性性假丝酵母菌。 白念珠菌在不同菌株之间具有很大的表型多样性，能够稳定地在 口腔或引起上皮损伤，导致免疫系统或OPC清除。然而， 不同菌株之间控制这些疾病表型差异的遗传位点尚不清楚。至 针对这一点，两个菌株529L和SC5314分别是一种稳定的定殖者和害虫，分别与 产生无性繁殖后代。在覆盖约1%的标记位置上对后代基因组进行测序 基因组。伴性生殖过程中的高重组率促进了19个QTL区域的定位 用铬释放法检测上皮损伤表型。目标一号将测试这些基因内的特定基因座 识别免疫系统损伤和清除的遗传决定因素的QTL 区分菌株的坚持性。此外，还将进行细丝形成的QTL分析，如 在一些后代中，形成和寄主细胞损伤是可分离的表型。 白色念珠菌使用丝状化破坏上皮表面，并进展为播散性系统性 感染。当前的成丝模型不能解释在成丝方面的显著差异 白色念珠菌分离株。为了识别物种范围内的丝状化调节因子，我们将使用QTL技术 AIM 2中4个具有不同丝状表型的菌株。所有配对的QTL都将揭示基因 在30oC和30oC的三种不同诱导介质上生长时，调节丝化表型的差异 37摄氏度，模拟人类宿主的口腔和体内温度。丝状化表型将 使用一种新颖的高通量视觉分析程序进行评分。因此，数量遗传的建立 在无性生殖物种中的方法将极大地加强对白色念珠菌致病调节因子的识别。 作为一名研究生，我的目标是成为一名科学家，他的研究汇集了多门科学 纪律。在追求这些目标的同时，我将在替补席上和电脑前发展我的技能，以弥合 信息学和生物学之间的鸿沟，在科学中发挥着越来越重要的作用。在整个项目中，我将 通过向当地和国际的科学观众展示这部作品来培养我的沟通技能， 与其他科学家合作，撰写我的作品，向科学界和普通人更广泛地传播 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.