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

描述（由申请人提供）：侵袭性曲霉病（IA）是白血病和骨髓移植患者最常见的感染性死亡原因。烟曲霉（Aspergillus fumigatus）是一种丝状真菌，是IA最常见的病因，它的分生孢子被吸入并在肺部发芽。像所有丝状真菌一样，烟曲霉通过胚芽管和后来的分枝经历高度极性的生长。这种高度极尖的生长使烟曲霉能够侵入血管和组织，导致IA的坏死特征。尽管极性生长对IA具有重要意义，但对烟曲霉极性生长的分子机制知之甚少。拟议的研究将使用微阵列分析来鉴定烟曲霉极性生长过程中差异转录和/或不对称定位的基因。利用从同步培养中分离的RNA，在胚管和分枝萌发前后以及菌丝和分枝伸长期间，生成极性生长期间表达的基因的时间谱。利用激光微捕获技术从胚管、菌丝和分枝的特定区域分离RNA，生成极性生长过程中表达的基因空间图谱。RNA将被标记并杂交到现有的PFGRC A. fumigatus微阵列中，并分析其表达模式。鉴定极性生长过程中差异转录和/或不对称定位的基因将为烟曲霉极性生长及其在IA中的作用的综合研究奠定基础。

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.