Cryptococcus gatti mating 1oci; mapping and gene study

描述（由申请方提供）：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品种（var.格鲁比湾neoformans和var. gattii）和交配类型（MAT α和MAT α）。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。这些致病差异的机制还不清楚。Cn var. Grubii是全世界隐球菌病最常见的原因; var.新型人感染主要在欧洲被发现。原发性和机会性感染，由于var。迄今为止，在澳大利亚、东南亚和南美洲均有分布，而在北美洲很少有报道。这种流行病学已经发生了巨大的变化，目前的报告，一个主要的var。加拿大不列颠哥伦比亚省发生人畜感染格特病疫情。目前，Cn交配正在进行深入研究，以确定真菌毒力和MAT α之间观察到的联系，并了解调控信号通路。最近，MAT α和MAT α基因座从变种。格鲁比和瓦尔目前，许多MAT特异性基因正在深入研究其在真菌生物学和毒力中的作用。然而，这些强大的分子遗传学分析尚未扩展到var。gattii，这将是必不可少的，以更好地了解其发病机制和更有效的治疗方法的发展。新兴知识从瓦尔。格鲁比和瓦尔在该实验室中应用了新形螨的DNA，以开发基于DNA的快速测试，以鉴定所有品种和交配类型;对MAT α/α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。目前的建议建立在这些调查的重点完全在var。加提。我们的具体目标是：（i）识别，定位和系统发育研究的基因，包括MAT α基因座，和（ii）表征的变种。gattii STE 12 α 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更好地了解var。通过提供（a）包含MAT α基因座的基因的遗传图谱，（B）STE 12 α在生物学和毒力中的作用的表征，和（c）用于真菌毒力的未来遗传研究的框架，来鉴定gattii致病性。

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.