Coccidioidomycosis:Genome Comparison, Selection and Transcription.

描述(由申请人提供)：我们的长期目标是开发预防和治疗球孢子菌病的方法，球孢子菌病是一种由球孢子菌和球孢子菌引起的系统性真菌疾病，在其他方面健康的人类。合作的调查人员是约翰·泰勒和加里·科尔，他们分别是研究球虫分子发育和进化生物学的实验室的主任。我们在这个提案中的目标是将比较基因组学和基因表达的工具集中在球孢子虫上，以确定对致病性和毒力重要的基因。我们的两个发现支持我们的建议：1)破坏已知对球孢子虫致病很重要的基因，降低其在哺乳动物中的毒力；2)球孢子虫显示出五个地理种群之间的遗传变异。每个球虫物种及其非致病亲缘种的基因组的完整、注解的可获得性是我们项目的主要支持支柱。我们可以通过在基因组中搜索致病基因，同时考虑自然变异，极大地增加治疗或预防的靶点数量。我们将通过对小鼠的毒力测试来评估我们关于这些基因的假设。我们的具体目标是：识别球果类植物与钩果类植物相比所特有的基因，识别球果类植物与钩果类植物之间存在正向选择的基因，以及识别球果类植物在腐生和寄生阶段存在显著转录差异的基因，无论是在体外还是体内。从这一组正向选择并在寄生阶段上调的独特基因中，我们将识别一组可能的致病基因库，我们将通过评估野生型菌株、目的基因已被敲除的WT株和替换了目的基因的KO株的小鼠的毒力来测试这些基因。通过现有的合作，我们的实验室已经研究并发表了球孢子虫致病基因的自然选择，并评估了腐生期和寄生期的转录。与公共卫生相关：近10%的美国人生活在球孢子菌病流行的地区，约5%的感染者发展为危及生命的疾病。有症状的感染提供长期免疫力，因此接种疫苗是可能的。同样，当致病基因被禁用时，毒力会降低，这表明针对这些基因产物的药物靶向应该是有效的。

DESCRIPTION (provided by applicant): Our long-term objective is to develop methods to prevent and treat coccidioidomycosis, a systemic fungal disease of otherwise healthy humans caused by the fungi Coccidioides immitis and Coccidioides posadasii. The collaborating investigators are John Taylor and Garry Cole, directors of laboratories that study Coccidioides molecular developmental and evolutionary biology, respectively. Our goal in this proposal is to focus the tools of comparative genomics and gene expression on Coccidioides to identify genes important to pathogenicity and virulence. Two of our findings underlie our proposal: 1) disruption of genes known to be important to the pathogenicity of Coccidioides reduces its virulence in mammals, and 2) Coccidioides shows genetic variation among five geographic populations. The availability of complete, annotated genomes of each /coccidioides species and the genome of their non-pathogenic relative, Uncinocarpus reesii, is a major pillar of support for our project. We can greatly increase the number of targets for therapy or prevention by searching the genome for pathogenicity genes, while accounting for natural variation. We will evaluate our hypotheses about these genes by virulence tests in mice. Our specific aims are to: identify genes unique to Coccidioides as compared to Uncinocarpus, identify genes that show positive selection between Coccidioides species and compared to Uncinocarpus, and identify genes in Coccidioides with significant transcription differences between the saprobic and parasitic phases, both in vitro and in vivo. From this cadre of unique genes which are under positive selection and upregulated during the parasitic phase, we will identify a pool of putative pathogenicity genes that can we will test by assessing virulence in mice of the wild-type strain, the WT strain in which the gene of interest has been knocked out, and the KO strain with the gene of interest replaced. Via existing collaboration, our laboratories have studied and published on natural selection of Coccidioides pathogenicity genes and assessed transcription in the saprobic and parasitic phases. Relevance to public health: Nearly 10% of Americans live in areas endemic to coccidioidomycosis, and approximately 5% of those infected develop life-threatening disease. Symptomatic infections confer long term immunity, so vaccination is possible. Likewise, virulence is reduced when pathogenicity genes are disabled, which indicates that pharmaceutical targeting of these gene products should be efficacious.