Collaborative Research: Sclerotization Mechanisms that Control Physical Properties of Insect Cuticle

昆虫外骨骼主要由两种结构聚合物组成，蛋白质和多糖甲壳素。在发育的每个阶段，昆虫必须产生具有适当的机械性能（强度，硬度，柔韧性）组合的外骨骼，以提供结构支撑，保护和移动性。这部分是通过在称为鞣制或硬化的过程中对结构聚合物进行化学改性来实现的。本跨学科研究计划将利用遗传学、基因组学、蛋白质组学、生物化学、分子生物学和材料科学研究赤拟谷盗（Tribolium castaneum）的菌核形成过程。合作研究小组将测试这一假设，即来自外骨骼不同区域的角质层物理特性的差异是由底层表皮表达的不同蛋白质和交联剂的出现促进的，这些蛋白质和交联剂被组织成不同的纳米结构。这一假设将通过使用RNA干扰来选择性地抑制被假定参与硬化的结构蛋白和酶的基因的表达来部分地检验。 将通过昆虫活力和光学和扫描电子显微镜定性评价所得表型，并通过动态力学分析和原子力显微镜定量评价所得表型。研究产生的更广泛的影响将包括对本科生、研究生和博士后学生的教育和培训。扩大参与科学的机会的具体努力将包括哈斯克尔印度民族大学的本科生参与KU的研究，并通过KSU的工程和科学计划中的妇女计划向初中和高中女生推广。从这个项目的结果将导致更好地了解昆虫角质层硬化，合理的目标设计的新型生物合理的方法选择性控制害虫和模板设计的新型纳米结构材料。

The insect exoskeleton is primarily composed of two structural polymers, protein and the polysaccharide chitin. At each stage of development an insect must produce an exoskeleton with the proper combination of mechanical properties (strength, hardness, flexibility) that affords structural support, protection and mobility. This is accomplished in part by chemical modifications of the structural polymers in a process known as tanning or sclerotization. This interdisciplinary project will make use of genetics, genomics, proteomics, biochemistry, molecular biology, and materials science to investigate the sclerotization process in the red flour beetle, Tribolium castaneum. The collaborative research team will test the hypothesis that differences in physical properties of cuticle from distinct regions of an exoskeleton are promoted by the occurrence of different sets of proteins and cross-linking agents expressed by the underlying epidermis, which become organized into different nanostructures. This hypothesis will be tested in part by the use of RNA interference to selectively suppress expression of genes of structural proteins and enzymes postulated to be involved in sclerotization. Resulting phenotypes will be evaluated qualitatively by insect viability and optical and scanning electron microscopy and quantitatively by dynamic mechanical analysis and atomic force microscopy. Broader impacts resulting from the research will include education and training for undergraduate, graduate, and postdoctoral students. Specific efforts at broadening opportunities for participation in science will include involvement of undergraduate students from Haskell Indian Nations University in the research at KU and outreach to middle school and high school girls through programs of the Women in Engineering and Science Program at KSU. The results from this project will lead to a better fundamental understanding of insect cuticle sclerotization, a plausible target for design of novel biorational methods for selective control of insect pests and a template for design of novel nanostructured materials.