Temporal and spatial profiling of gene expression during polar growth of Aspergil

描述(申请人提供)：侵袭性曲霉病(IA)是白血病和骨髓移植患者最常见的感染死亡原因。烟曲霉菌是引起IA的最常见的丝状真菌，其分生孢子被吸入并在肺中萌发。像所有丝状真菌一样，烟曲霉菌通过芽管和后来的分枝进行高度极性的生长。这种高度极化的尖端生长允许烟曲霉菌侵入血管和组织，导致IA的坏死特征。尽管极性生长对烟曲霉菌的生长具有重要意义，但对其分子机制却知之甚少。这项拟议的研究将使用微阵列图谱来识别在烟曲霉极地生长过程中差异转录和/或不对称定位的基因。在极地生长期间表达的基因的时间分布将使用从胚管和分枝出现之前和之后以及菌丝和分枝伸长期间的同步培养中分离的RNA来产生。利用激光显微捕捉技术，从胚管、菌丝和枝条的特定区域分离出RNA，将生成极地生长期间表达的基因的空间分布。RNA将被标记并与现有的PFGRC烟曲霉菌微阵列杂交，并将分析表达模式。鉴定在极地生长过程中差异转录和/或不对称定位的基因将为全面研究烟曲霉极地生长及其在IA中的作用奠定基础。 公共卫生相关性：侵袭性曲霉病(IA)是一种免疫功能低下者的一种通常致命的疾病，当烟曲霉的孢子被吸入并在肺部生长时，就会引起这种疾病。像其他丝状真菌一样，烟曲霉向环境中发出被称为菌丝的长管细胞，寻找营养，而在IA中，正是这些菌丝导致宿主组织的破坏。这项拟议的研究将识别允许烟曲霉菌产生菌丝的基因，从而发现对抗IA的新方法。

DESCRIPTION (provided by applicant): Invasive aspergillosis (IA) is the most frequent infectious cause of death in leukemia and bone marrow transplant patients. The conidia of Aspergillus fumigatus, the filamentous fungus that is the most common cause of IA, are inhaled and germinate in the lung. Like all filamentous fungi A. fumigatus undergoes highly polar growth via germ tubes and later branches. This highly polar tip growth allows A. fumigatus to invade blood vessels and tissues resulting in the necrosis characteristic of IA. Despite the importance of polar growth to IA, little is known about the molecular mechanisms of polar growth in A. fumigatus. The proposed research will use microarray profiling to identify genes that are differentially transcribed and/or asymmetrically localized during polar growth in A. fumigatus. Temporal profiles of genes expressed during polar growth will be generated using RNA isolated from synchronous cultures just before and after germ tube and branch emergence and during elongation of hyphae and branches. Spatial profiles of genes expressed during polar growth will be generated using RNA isolated from specific regions of germ tubes, hyphae and branches with laser microcapture techniques. RNA will be labeled and hybridized to existing PFGRC A. fumigatus microarrays and expression patterns will be analyzed. Identification of genes that are differentially transcribed and/or asymmetrically localized during polar growth will lay the foundation for a comprehensive research program focusing on polar growth in A. fumigatus and its role in IA. PUBLIC HEALTH RELEVANCE: Invasive aspergillosis (IA), an often fatal disease of the immunocompromised, is caused when the spores of Aspergillus fumigatus are inhaled and grow in the lung. Like other filamentous fungi, A. fumigatus sends out long tubular cells known as hyphae into the environment searching for nutrients and in IA it is these hyphae which cause the destruction of host tissue. The proposed research will identify genes that allow A. fumigatus to make hyphae and so will uncover new ways of combating IA.