Biosynthetic/Biomimetic Studies in Insects

本研究旨在研究昆虫发育过程中幼体激素（JH）功能的关键中间体，并将得到有机和大分子化学项目的支持。这项研究将导致JH作用的阐明，这将为昆虫控制的替代方法提供见解。昆虫中未知的内源性幼体和抗幼体将通过受体结合试验进行分离和表征，以指导分离、纯化和鉴定。这些无脊椎动物化合物可能是参与受体蛋白介导的染色体DNA转录的形态形成因子或抗形态形成因子。1. 内生Juvenoids。幼体激素（JH）的作用可以在体内被五千多种合成的幼体模仿，其中许多与JH本身无关。利用SUNY， Stony Brook开发的氚和I-125标记的JH模拟物发现烟草角虫靶细胞核中存在独特的幼体结合位点。这些位点不识别JH同源物。因此可以预测，在未成熟昆虫体内存在内源性小分子，这些小分子是这些幼体受体的天然配体。利用甲基戊二烯氚或s -31183氚（或其光敏性类似物）的结合，从早期烟草角虫幼虫中纯化竞争结合材料，以确定这些天然形态因子的存在和结构。2. 白蚁等级分化的抑制因子。士兵白蚁的头部分泌大量的防御分泌物；此外，现在已经发现存在其他物质，可以抑制甲氧苯醚诱导的工蜂蜕皮为前驱兵。白蚁工蚁和东部地下白蚁的幼虫是分离刺激种姓分化的甲氧二烯受体的丰富资源，而士兵和若虫体内含有抑制甲氧二烯这一作用的信息素。建立了一种体外生化检测方法，通过光亲和标记法检测甲氧二烯诱导的血淋巴JH结合蛋白的变化。

This research is on characterizing the key intermediates in the functioning of juvenile hormones (JH) in insect development and will be supported by the Organic and Macromolecular Chemistry Program. This research will lead to the elucidation of JH action which will provide insights into alternative methods of insect control. Unknown endogenous juvenoids and anti-juvenoids in insects will be isolated and characterized by the use of receptor binding assays to guide fractionation, purification, and authenication. These invertebrate compounds may be morphogens or anti-morphogens involved in receptor protein-mediated transcription of chromosomal DNA. 1. Endogenous Juvenoids. Juvenile hormone (JH) action can be mimicked in vivo by over five thousand synthetic juvenoids, many unrelated to JH itself. Tritium and I-125 labeled JH mimics developed at SUNY, Stony Brook were used to discover the existence of unique juvenoid binding sites in target cell nuclei of the tobacco hornworm. These sites do not recognize JH homologs. Thus it is predicted that endogenous small molecules are present in immature insects which are natural ligands for these juvenoid receptors. Using the binding of tritium-methoprene or tritium-S-31183 (or their photolabile analogs), the competitive binding materials will be purified from early instar Manduca (tobacco hornworm) larvae to establish the existence and structure of these natural morphogens. 2. Inhibitors of Termite Caste Differentiation. Soldier termites produce abundant defense secretions in their head; in addition, it has now been found that other substances are present, which can inhibit the methoprene-induced molting of workers into presoldiers. Termite workers and larvae of the Eastern subterranean termite Reticulitermes flavipes are an abundant resource for isolation of methoprene receptor involved in stimulating caste differentiation, while soldiers and nymphs contain inhibitory pheromones which block this action of methoprene in vivo. An in vitro biochemical assay has been developed by which changes in hemolymph JH binding proteins induced by methoprene are detected by photoaffinity labeling.