Collaborative Research: Integrating Molecular and Material Evolution of Spider Aqueous Glues

蜘蛛的惊人多样性和它们作为地球仪主要捕食者的角色在很大程度上可以归功于它们对丝的创新使用。例如，金色圆网蜘蛛或黑寡妇可以纺出六种不同类型的干纤维和一种湿的粘性丝。这些蜘蛛和它们的亲戚（大多样性蜘蛛总科）的湿粘性丝为它们提供了更大的猎物保留更低的材料成本比其他蜘蛛群体纺的干猎物捕获丝。此外，这些蚕丝胶在各种环境中实现了可降解性，包括挑战商业胶的极端湿度条件。来自三个机构的多学科团队将研究粘附蛋白组分的变化如何与胶水材料特性的变化相关。18个目标物种的湿粘丝在吸湿率、材料效率和对湿度的响应方面存在显著差异。因此，组成蛋白质的发现将允许设计具有定制特性的环境友好型胶水。此外，网络建设蜘蛛为科学教育工作者提供了许多机会，使他们能够将生物学，化学，物理学和数学融入自然世界。研究团队将指导本科生和硕士生，并将研究纳入本科课程。此外，团队成员还将在弗吉尼亚州农村公立小学开展科学丰富活动，为初中和高中科学教师举办研讨会，并指导纽约市高中学生完成原创研究项目。蜘蛛水胶的进化多样性提供了一个独特的机会，与其他生物粘合剂相比，以确定分子构建块如何有助于粘合的不同方面。通过在系统发育框架内整合转录组学，蛋白质组学和生物力学，拟议的实验将确定与界面粘附，胶内凝聚力和湿度响应性共同进化的蛋白质特征。目的1通过分析5种蜘蛛和3个外类群的丝腺类型的转录多样性，确定与湿粘丝进化相关的基因表达变化。它还调查了另外13个物种的产生粘合剂的丝腺中表达水平的演变，这些物种在不同的湿度水平下构建不同的网络类型和饲料。目的2鉴定并定量分析18种昆虫粘丝蛋白的组成及其翻译后修饰。目的3测定18种同种蚕丝材料在不同湿度下的湿粘性能。这些综合实验将有助于理解关键创新的起源和分子基础。具体来说，他们将确定基因表达变化的程度和制造新型蚕丝所需的新基因。拟议的工作将跟踪胶蛋白特征的进化速率，包括翻译后修饰，这是目前知之甚少。最后，胶材料的性能测量将测试的假设，即湿度响应的蜘蛛胶液滴已经演变为最佳性能的湿度，其中蜘蛛物种通常foreages.This奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的知识价值和更广泛的影响审查标准。

The spectacular diversity of spiders and their role as key predators across the globe can largely be attributed to their innovative uses of silk. For instance, a golden orb-web spider or a black widow can spin six different types of dry fibers and a wet adhesive silk. The wet adhesive silks made by these spiders and their relatives (the megadiverse superfamily Araneoidea) afford them greater prey retention for a lower material cost than the dry prey capture silk spun by other spider groups. Furthermore, these silk glues achieve adhesiveness in a wide variety of environments, including extreme humidity conditions that challenge commercial glues. A multidisciplinary team from three institutions will investigate how variation in adhesive protein components relates to variation in the glue's material properties. The wet adhesive silks of the 18 target species have significant variation in adhesiveness, material efficiency, and response to humidity. Thus, the discovery of constituent proteins will allow design of environmentally friendly glues with tailored properties. Furthermore, web-building spiders offer many opportunities for science educators to integrate biology, chemistry, physics, and mathematics as they engage their students in the natural world. The team of investigators will mentor undergraduate and Master's students, as well as incorporate the research into undergraduate course curricula. Additionally, team members will offer science enrichment activities at rural Virginia public elementary schools, run workshops for middle and high school science teachers, and mentor New York City high school students to complete original research projects.The evolutionary diversity of spider aqueous glues offers a unique opportunity compared to other bioadhesives to determine how molecular building blocks contribute to different aspects of adhesion. By integrating transcriptomics, proteomics, and biomechanics within a phylogenetic framework, the proposed experiments will pinpoint protein characteristics that co-evolve with interfacial adhesion, intra-glue cohesion, and humidity responsiveness. Objective 1 identifies shifts in gene expression associated with the evolution of wet adhesive silk by profiling transcriptional diversity in each of the silk gland types of 5 divergent araneoid species and 3 outgroup taxa. It also investigates evolution of expression levels in the adhesive-producing silk glands of an additional 13 species that build different web types and forage under divergent humidity levels. Objective 2 identifies and quantitates the proteins that compose adhesive silks of all 18 species, as well as their post-translational modifications. Objective 3 measures wet adhesive silk material properties for the same 18 species at different humidities. These integrated experiments will contribute to understanding the origin and molecular underpinnings of a key innovation. Specifically, they will determine the degree to which gene expression shifts and new genes were required to make a novel type of silk. The proposed work will track evolutionary rates in glue protein characteristics, including post-translational modifications, which is currently poorly understood. Finally, glue material property measurements will test the hypothesis that humidity responsiveness of spider glue droplets has evolved for optimal performance at the humidity in which a spider species typically forages.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.