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

由动物和植物产生的粘合剂为工程和消费应用提供了新材料。这些生物体如何产生和使用它们的生物粘合剂是理解它们如何机械地发挥作用以及它们如何进化的关键。一小群蜘蛛制造出了一种特殊的胶水，它在使用时具有水一样的流动性，在凝固时具有橡胶般的韧性。据预测，这种胶水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，蛾捕捉器中的胶水的功能和遗传学将与不捕捉蛾的蜘蛛中的胶水进行比较。胶水的强度和韧性将在现场和实验室中使用专用测试机进行测量。胶水基因的位置和序列，以及这些基因被激活的组织将被揭开。一个新的计算机模型将解释胶水是如何在几秒钟内从流动的液体变成坚韧的粘合剂的，以及这是如何让胶水粘在蛾的鳞片上的。这项研究将部分由本科生和高中生进行，他们在研究人员的指导下进行为期一年和两年的学徒培训，为STEM职业提供培训。该团队的综合研究工作将为推进利用具有新型机械性能的天然材料开发工程粘合剂奠定基础。对生物材料的全面理解应该包括其在生物、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，是这种类型的调查的优秀系统，因为它们的机械行为是直接观察到的生物体的生态环境。对于大多数圆织蜘蛛来说，有一种丰富的猎物是难以捉摸的：飞蛾。但飞蛾是被蜘蛛捕捉的。它们使用的捕获胶具有低粘度，当与蛾接触时，在蜘蛛胶中测量的蜘蛛胶中具有最高的粘合强度和韧性。这个项目测试的假设，这种捕获胶是关键的适应Cyrtarachninae捕捉蛾。胶水的速度和扩散程度将通过高速显微摄像来测量，以测试竞争的微流体模型。将在现场和实验室中使用拉脱张力测试测量胶的粘合行为（捕获过程中的第二步），量化为粘合强度（N）和粘合韧性（Nm-2）。将使用基因组学、转录组学和蛋白质组学方法的组合来鉴定胶蛋白的基因。最后，基因组和机械性状将被映射到Cyrtarachninae和假设的共同祖先重建的状态的系统发育。由于早期和持续的研究促进了学生在STEM职业中的保留和承诺，在这项研究的每个阶段，高中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年或两年的密集研究培训。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值进行评估，更广泛的影响审查标准。

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.