Cryptococcus gatti mating loci; mapping and gene study

加蒂隐球菌交配位点；

• 批准号: 6682120
• 负责人: VISHNU CHATURVEDI
• 金额: $ 7.81万
• 依托单位: WADSWORTH CENTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-15 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6682120
• 关键词: Cryptococcus neoformans; biochemical evolution; biological signal transduction; biotechnology; cryptococcosis; functional /structural genomics; fungal genetics; gene targeting; genetic library; genetic mapping; genetic screening; laboratory mouse; microorganism reproduction; molecular genetics; mutant; nucleic acid purification; nucleic acid sequence; plasmids; transcription factor; transfection; virulence

DESCRIPTION (provided by applicant): Cryptococcus neoformans (Cn) causes cryptococcosis, a fungal meningoencephalitis. The pathogen has genetically distinct varieties (var. grubii, var. neoformans, and var. gattii) and mating types (MATalpha and MATalpha). These varieties elicit different host responses in normal and immunocompromised individuals. The mechanisms underlying these pathogenic differences are not well understood. Cn var. grubii is the most common cause of cryptococcosis worldwide; var. neoformans infections have been mostly recognized in Europe. Both primary and opportunistic infections due to var. gattii were till recently reported from Australia, Southeast Asia and South America with rare reports from North America. This epidemiology has changed dramatically with the current report of a major var. gattii outbreak in humans and animals in British Columbia, Canada. Currently, Cn mating is under intensive investigations to define the observed linkage between fungal virulence and MATalpha, and to understand the regulatory signaling pathways. Recently, MATalpha and MATalpha loci from var. grubii and var. neoformans were mapped, and many MAT-specific genes are under intensive study for their role in fungal biology and virulence. However, these powerful molecular genetic analyses have not yet been extended to var. gattii, which will be essential for better understanding of its pathogenesis and the development of more effective therapy. The emerging knowledge from var. grubii and var. neoformans was applied in this laboratory to develop DNA based rapid tests to identify all varieties and mating types; further study of MATalpha/alpha pheromones revealed variety specificity, different copy numbers, and chromosomal locations, and a potential for cross-variety mating and/or hybridization. The current proposal builds upon these investigations by focusing exclusively on var. gattii. Our specific goals are: (i) identification, mapping and phylogenetic studies of genes comprising MATalpha locus, and (ii) characterization of var. gattii STE12alpha cDNA, construction of gene knockout mutants, and study of mutant phenotypes and pathogenic potential. This study may lead to better understanding of var. gattii pathogenicity by providing (a) a genetic map of genes comprising MATalpha locus, (b) characterization of the role of STE12alpha in biology and virulence, and (c) a framework for future genetic investigations of fungal virulence.

描述（由申请人提供）：新型隐球菌（Cn）引起隐球菌病，一种真菌性脑膜脑炎。该病原体具有遗传上不同的变种（var. grubii、var. neoformans 和 var. gattii）和交配类型（MATalpha 和 MATalpha）。这些品种在正常和免疫功能低下的个体中引起不同的宿主反应。这些致病差异背后的机制尚不清楚。 CN 变种grubii 是全世界隐球菌病最常见的病因；变种新型隐球菌感染主要在欧洲得到认可。由变种引起的原发性感染和机会性感染。直到最近，澳大利亚、东南亚和南美洲也有报道称格特氏菌，北美的报道很少。随着当前主要变种的报告，这种流行病学发生了巨大变化。加拿大不列颠哥伦比亚省的人类和动物中爆发了加特衣疫情。目前，Cn 交配正在深入研究中，以明确观察到的真菌毒力和 MATα 之间的联系，并了解调控信号通路。最近，来自 var 的 MATalpha 和 MATalpha 基因座。格鲁比和变种新型隐球菌已被绘制出来，并且许多 MAT 特异性基因正在对其在真菌生物学和毒力中的作用进行深入研究。然而，这些强大的分子遗传学分析尚未扩展到变种。 gattii，这对于更好地了解其发病机制和开发更有效的治疗方法至关重要。来自变种的新兴知识。格鲁比和变种该实验室应用新型隐球菌来开发基于 DNA 的快速测试，以识别所有品种和交配类型；对 MATalpha/alpha 信息素的进一步研究揭示了品种特异性、不同的拷贝数和染色体位置，以及跨品种交配和/或杂交的潜力。当前的提案以这些调查为基础，专门关注 var。加蒂。我们的具体目标是：(i) 对包含 MATalpha 基因座的基因进行鉴定、作图和系统发育研究，以及 (ii) var 的表征。 gattii STE12alpha cDNA、基因敲除突变体的构建以及突变体表型和致病潜力的研究。这项研究可能会导致人们更好地理解 var。通过提供（a）包含 MATalpha 基因座的基因遗传图谱，（b）STE12alpha 在生物学和毒力中的作用特征，以及（c）未来真菌毒力遗传研究的框架，来研究 gattii 致病性。