SGER: Role of Cytochrome P450 in Chemosensory Mediation of Oviposition in Papilio polyxenes

SGER：细胞色素 P450 在凤蝶产卵化学感应介导中的作用

• 批准号: 0614726
• 负责人: May Berenbaum
• 金额: --
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2007-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0614726&HistoricalAwards=false
• 关键词: SGER; Role; Cytochrome; P450; Chemosensory

SGER: Role of cytochrome P450 in chemosensory mediation of oviposition in Papilio polyxenesMay Berenbaum, University of Illinois at Urbana-ChampaignUnderstanding how plant-feeding insects such as the Lepidoptera, the butterflies and moths, recognize and utilize the plants on which they feed is key to understanding the diversification of this exceptionally species-rich group of organisms. The inability to identify specific genes underlying how hostplants are identified and processed has been a major obstacle; although genome projects provide enormous inventories the challenge remains to assign function to genes affecting behavior and physiology and substantial knowledge gaps characterize the ecology of most model organisms such as Drosophila melanogaster, the "fruit fly" of genetics fame. Key genes mediating plant-insect interactions are the cytochrome P450 monooxygenases, enzymes responsible not only for detoxifying insecticidal plant compounds consumed by leaf-feeding caterpillars but also breaking down plant odorants detected by the antennae and legs of female butterflies searching for plants on which to lay eggs . An extraordinary opportunity for characterizing P450s within a single species that influence hostplant use by caterpillars and hostplant recognition by female butterflies is presented by the black swallowtail Papilio polyxenes. Its chemical ecology is uniquely well-characterized, stimulants for egg-laying as well as toxic chemicals that affect caterpillar growth are known. As well, for a non-model species, its molecular biology is unusually well-documented, with P450 enzymes CYP6B1 and CYP6B3 in caterpillar guts contributing to detoxification of insecticidal compounds in hostplants, and CYP4G28 characterized from the legs of female butterflies possibly involved in hostplant recognition by female butterflies. Thus, the objectives of this SGER are to determine CYP4G28 function by 1. determining whether this gene is expressed specifically in the sensory structures used by female butterflies for "tasting" and recognizing their hostplants prior to laying eggs (using the techniques of immunolocalization and in situ hybridization); 2. molecular modeling to determine whether chemicals known to stimulate egg-laying "fit" into the active site of the CYP4G28 protein; 3. conducting behavioral bioassays to determine if inhibiting the P450s in butterfly forelegs prohibits female butterflies from recognizing their hostplants. Broader impacts resulting from the proposed activities include interdisciplinary training encompassing elements of phytochemistry, molecular biology, and entomology; students will receive broad-based training essential for competitiveness in the 21st century. Findings will be published in scientific journals, in a textbook integrating molecular biology and chemical ecology, and in popular writings and public lectures. Among other potential benefits to society at large will be a greater understanding of the process by which cytochome P450s evolve. These enzymes contribute to the development of insecticide resistance and the acquisition of new hostplants, including crops, phenomena of tremendous ecological and economic importance.

SGER：细胞色素P450在多形凤蝶产卵的化学感受介导中的作用May Berenbaum，伊利诺伊大学厄巴纳-香槟分校了解食草昆虫（如鳞翅目、蝴蝶和蛾）如何识别和利用它们所食的植物是了解这一异常物种丰富的生物群多样化的关键。 无法确定宿主如何识别和加工的具体基因一直是一个主要障碍;虽然基因组计划提供了巨大的库存，但挑战仍然是分配影响行为和生理的基因的功能，并且大部分模式生物的生态学特征是大量的知识空白，如果蝇（Drosophila melanogaster），遗传学上的“果蝇”。介导植物-昆虫相互作用的关键基因是细胞色素P450单加氧酶，这种酶不仅负责解毒食叶毛虫所消耗的杀虫植物化合物，而且还负责分解寻找产卵植物的雌性蝴蝶的触角和腿所检测到的植物气味。 一个非凡的机会，表征P450在一个单一的物种，影响寄主利用毛虫和寄主识别的雌性蝴蝶是由黑色燕尾凤蝶。它的化学生态是独特的，产卵的刺激剂以及影响毛虫生长的有毒化学物质是已知的。此外，对于非模式物种，其分子生物学异常有据可查，毛毛虫肠道中的P450酶CYP 6 B 1和CYP 6 B 3有助于宿主植物中杀虫化合物的解毒，而CYP 4G 28则来自雌性蝴蝶的腿，可能参与雌性蝴蝶对宿主植物的识别。 因此，本SGER的目的是通过1.确定该基因是否在雌性蝴蝶产卵前用于“品尝”和识别其寄主的感觉结构中特异性表达（使用免疫定位和原位杂交技术）; 2.分子建模以确定已知刺激产卵的化学物质是否“适合”进入CYP 4G 28蛋白的活性位点; 3.进行行为生物测定以确定抑制蝴蝶前腿中的P450是否会阻止雌性蝴蝶识别它们的寄主植物。 拟议的活动产生的更广泛的影响包括跨学科培训，包括植物化学，分子生物学和昆虫学的元素;学生将接受基础广泛的培训，这对21世纪世纪的竞争力至关重要。研究结果将发表在科学期刊上，在整合分子生物学和化学生态学的教科书中，以及在流行著作和公开讲座中。对整个社会的其他潜在好处之一是更好地了解细胞色素P450的进化过程。 这些酶有助于产生杀虫剂抗性和获得新的寄主植物，包括作物，这是具有巨大生态和经济重要性的现象。