Collaborative Research: RUI: Behavior and Evolution of the Novel Self-Curing Bioadhesive of Moth-Specialist Spiders

动植物生产的粘合剂为工程和消费应用提供了新的材料。这些生物如何生产和使用它们的生物粘合剂，是了解它们如何机械运作以及它们是如何进化的关键。一种非同寻常的胶水--涂抹时具有水一样的流动性，固化时具有橡胶般的韧性--是由一小群蜘蛛产生的。据预测，这种粘合剂对这些蜘蛛如何捕捉飞蛾至关重要，而其他蜘蛛很少能做到这一点。在这项研究中，捕蛾器中胶水的功能和遗传学将与不捕蛾的蜘蛛胶水中的胶水进行比较。这种胶水的强度和韧性将在现场和实验室使用专门建造的测试仪进行测量。胶基因的位置和序列，以及这些基因被激活的组织，都将被揭开。一个新的计算机模型将解释胶水如何在几秒钟内从流动的液体变成坚韧的粘合剂，以及胶水如何粘在蛾子的鳞片上。这项研究将部分由本科生和高中生进行，他们进行为期一年和两年的学徒培训，由调查人员指导，为STEM职业生涯提供培训。该团队的综合研究工作将为推进从具有新型机械性能的天然生产材料开发工程粘合剂奠定基础。对生物材料的全面理解应包括其在生物、生态和进化背景下的力学行为。生物粘合剂，如蜘蛛产生的胶水，是这类研究的优秀系统，因为它们的机械行为可以在有机体的生态环境中直接观察到。对于大多数编织圆球的蜘蛛来说，有一种丰富的猎物是难以捉摸的：飞蛾。但飞蛾是被角蜘蛛捕获的。他们使用的捕捉胶具有低粘度，当与飞蛾接触时，在蜘蛛胶中具有最高的粘合强度和韧性。这个项目测试了一种假设，即这种捕获胶是Cyrtarachninae捕捉飞蛾的关键适应。这种胶水的扩散速度和程度将用高速显微摄像技术进行测量，以测试相互竞争的微流体模型。胶水的粘合性能是捕获过程中的第二步，以粘接强度(N)和粘接韧性(Nm-2)表示，将在现场和实验室使用拉开张力测试进行测量。胶蛋白的基因将使用基因组、转录组和蛋白质组方法相结合的方法进行鉴定。最后，基因组和机械特征将被映射到Cyrtarachninae的系统发育上，并重建假想的共同祖先的状态。由于早期和持续的研究促进学生在STEM职业生涯中的保留和承诺，在本研究的每个阶段，高中生和大学生将成为长期学徒，在研究人员的直接监督下参加一到两年的强化研究培训。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Adhesives produced by animals and plants provide novel materials for engineering and consumer applications. How these organisms produce and use their biological adhesives is the key to understanding how they function mechanically and how they have evolved. An extraordinary glue -- with an unusual combination of water-like fluidity when applied and rubbery toughness when set -- is produced by a small group of spiders. This glue is predicted to be critical to how these spiders catch flying moths, which few other spiders can do. In this research, the function and genetics of glues in moth-catchers will be compared to those in glues of spiders that don’t catch moths. The glues’ strength and toughness will be measured in the field and in the lab using a purpose-built testing machine. The location and sequence of glue genes, and the tissues where these genes are activated, will be uncovered. A new computer model will explain how the glue changes from a flowing liquid to a tough adhesive in seconds, and how this allows the glue to stick to moth scales. This research will be conducted, in part, by undergraduates and high school students carrying out one- and two-year apprenticeships mentored by the investigators to provide training for STEM careers. The team’s integrated research efforts will lay groundwork for advancing development of engineered adhesives from naturally produced materials with novel mechanical properties. A comprehensive understanding of a biomaterial should include its mechanical behavior in its organismal, ecological, and evolutionary context. Bioadhesives, such as the glues produced by spiders, are excellent systems for this type of investigation because their mechanical behavior is directly observable in the organism's ecological context. For most orb-weaving spiders, one type of abundant prey is elusive: moths. But moths are captured by cyrtarachnine spiders. They use a capture glue that possesses low viscosity and when in contact with moths has the highest adhesive strength and toughness among spider glues measured among spider glues. This project tests the hypothesis that this capture glue is the key adaptation of the Cyrtarachninae for catching moths. The glue’s rate and extent of spreading will be measured with high-speed micro-videography to test competing microfluidic models. Adhesive behavior of the glue, the second step in the capture process, quantified as adhesive strength (N) and adhesive toughness (Nm-2), will be measured in the field and in the lab using pull-off tension tests. Genes for the glue proteins will be identified using a combination of genomic, transcriptomic, and proteomic approaches. Finally, genomic and mechanical traits will be mapped onto the phylogeny of the Cyrtarachninae and the states of the hypothetical common ancestor reconstructed. Because early and sustained research fosters retention and commitment of students in STEM careers, in each stage of this research, high school and college students will become long-term apprentices, participating for one or two years of intensive research training under direct supervision of the investigators.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.