REGULATION OF CECROPIN AND ATTACIN GENE EXPRESSION

昆虫基因表达的分子分析，与 值得注意的是，果蝇是个例外，它落后于 原核生物、酵母和脊椎动物。一种很有特点的昆虫 提供了可在分子水平上进行剖析的系统 通过鳞翅目昆虫的抗菌反应。 昆虫对感染的抵抗力主要是通过 限制进入血腔的结构性障碍。如果这些 结构性障碍因受伤或攻击而被破坏，潜在的 病原体或寄生虫可能进入血腔。为了生存 这些感染，昆虫进化出了一套活跃的次级 防御措施：(I)限制血淋巴流失和愈合伤口；(Ii)检测 并消除入侵者，以及(Iii)保护受伤的宿主，同时 结构性障碍和耗尽的防御措施得到恢复。一 主动防御细菌武器库的组成部分是 抗菌、血淋巴蛋白的调节合成。 这项拟议研究的长期目标是发现 编码基因表达调控的分子机制 昆虫抗菌蛋白。本提案的重点是 抗菌蛋白基因、基因的转录调控 结构和组织特异性表达。具体目标 是：(1)确定转录调控的贡献 肽聚糖对脂肪体天蚕素样蛋白(CLP)的调节作用 和阿特辛样蛋白(ALP)的合成；(2)分离和 鉴定编码CLP和ALP的SextA基因；(3)分析 与CLP和ALP基因相关的二级结构元件 幼稚和肽聚糖诱导的脂肪体；和(4)确定 已建立的鳞翅目细胞系是否表现出增强 抗菌蛋白基因转录及合成 肽聚糖引起的CLP和ALP水平升高 引导者。 拟议的研究将产生关于以下方面的新信息： 昆虫寄主-病原菌/寄生虫相互作用及(II)结构 以及昆虫基因的调控。这一知识可能有助于 人类和动物疾病的昆虫媒介的管理。

The molecular analysis of gene expression in insects, with the notable exception of Drosophila melanogaster, lags behind those in prokaryotes, yeast, and vertebrates. A well characterized insect system amenable to dissection at the molecular level is provided by the antibacterial response of lepidopteran insects. Resistance to infection in insects is accomplished largely via structural barriers that limit access to the hemocoel. If these structural barriers are disrupted via injury or attack, potential pathogens or parasites may gain access to the hemocoel. To survive these infections, insects have evolved a set of active secondary defenses that (i) limit hemolymph loss and heal wounds, (ii) detect and eliminate invaders, and (iii) protect the injured host while structural barriers and depleted defenses are restored. One component of the active defensive arsenal against bacteria is the regulated synthesis of antibacterial, hemolymph proteins. The long term goal of the proposed research is to discover molecular mechanisms regulating the expression of genes encoding insect antibacterial proteins. The present proposal focuses on transcriptional regulation of antibacterial protein genes, gene structure, and tissue specific expression. Specific objectives are: (1) to determine the contribution of transcriptional control to peptidoglycan regulation of fat body cecropin-like protein (CLP) and attacin-like protein (ALP) synthesis; (2) to isolate and characterize M. sexta genes encoding CLP and ALP; (3) to analyze secondary structural elements associated with CLP and ALP genes in naive and peptidoglycan-induced fat body; and (4) to determine whether established lepidopteran cell lines exhibit enhanced transcription from antibacterial protein genes and synthesize elevated levels of CLP and ALP in response to peptidoglycan elicitors. The proposed research will yield new information concerning (i) the insect host-pathogen/parasite interaction and (ii) the structure and regulation of insect genes. This knowledge may contribute to the management of insect vectors of human and animal disease.