Collaborative Research: Genetics and biomechanics of non-Newtonian prey capture adhesives across Panarthropoda

几组无脊椎动物产生捕获猎物的胶，这些胶沉积在丝绸上，分泌到四肢上，或者直接喷射到猎物身上。这些胶水的干燥时间和对湿度的反应在材料上是独特的，但它们在功能上是相似的，因为它们根据施加的力和它们的快速粘附而变化粘度。研究人员将研究来自三个远亲类群的10种猎物捕获胶的分子和物理特性——蛛形纲（蜘蛛和阿谀类）、苍蝇（掠食性萤火虫）和绒虫（丝绒蠕虫）。通过了解不同分子基的胶水性能的差异，可以为设计新的合成粘合剂建立必要成分的目录。这项研究将进一步加强代表性不足的少数民族在实地课程中的参与，研究继续证明，这对个人选择生态、进化和环境科学领域的职业至关重要。位于北卡罗来纳州高地的高地生物站（HBS）是阿巴拉契亚地区研究的重要资源，几十年来一直举办为期两周的实地课程“蜘蛛生物学”。本课程着重于野外鉴定、标本收集和保存。为了进一步提高公众对阿巴拉契亚地区蛛形纲动物的积极认识和兴趣，以及为不同的学生群体提供更多的实地考察机会，研究人员将通过以多样性为重点的奖学金、新的课程材料和通过学生参与对哈佛商学院蛛形纲动物收藏的贡献来支持学生出勤，从而加强现有课程。与同源来源的材料在选择压力下多样化不同，研究来自远亲生物的趋同进化的猎物捕获胶为探索构建这些粘合剂的必要和新颖成分提供了一个独特的机会。该项目将研究猎物捕获胶，以了解其分子成分对功能的贡献，并发现与功能，生态或形态相似性相关的共性。首先，靶向转录组学、DNA测序和糖基化分析将被用来重建来自每个物种的胶的生物分子组织。这将是第一个研究胶水基因长度和重复对胶水功能的重要性的研究，也是第一个比较多种生物粘合剂翻译后o糖基化修饰的研究。其次，在粘合剂操作过程中的力传导测量将允许记录和分析每种胶水的生物力学特性。结合全长序列，可以直接推断出粘接序列的力学潜能，包括重复数和单位复杂度对粘接韧性和延展性的影响。最后，我们将重建基因树，以评估支持平行或收敛进化的猎物捕获粘合剂。相似的序列同一性将支持功能选择在猎物捕获粘合基因进化中的收敛强度。另外，粘合转录本之间的序列一致性差表明，猎物粘附存在多种生化机制，为仿生合成提供了令人兴奋的新途径。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Several groups of invertebrate species produce prey capture glues that are deposited on silks, secreted onto limbs, or squirted directly onto prey. These glues are materially unique in their drying times and reaction to humidity, but they are functionally similar in that they vary in viscosity based on applied forces and their rapid adhesion. The researchers will investigate the molecular and physical attributes of prey capture glues from 10 species in three distantly related groups - arachnids (spiders and opilionids), flies (predatory glow worms), and onychophorans (velvet worms). By understanding the differences in glue properties with respect to their molecular bases, a catalog of necessary components can be established for the design of new synthetic adhesives. This research will furthermore enhance participation of underrepresented minorities in field coursework, which research continues to demonstrate to be critically important to individuals choosing careers in ecology, evolution, and environmental sciences. The Highlands Biological Station (HBS) in Highlands, North Carolina, is an important resource for research in the Appalachian region and has hosted the two-week field class, “The Biology of Spiders,” for several decades. This class focuses on field identification, specimen collection, and preservation. With the twin goals of furthering positive public perception and interest in arachnids within the Appalachian region, and improving access to fieldwork opportunities for diverse student populations, the researchers will enhance the existing course by supporting student attendance via diversity-focused scholarships, new course material, and contributions to the HBS arachnid collection through student participation.Unlike materials with homologous origin that diversify under selective pressure, investigating convergently evolved prey capture glues from distantly related organisms offers a unique opportunity to explore the necessary and novel components for constructing these adhesives. This project will examine prey capture glues with the broad goals of understanding the contribution of their molecular components to function, and discovering the commonalities associated with functional, ecological, or morphological similarity. First, targeted transcriptomics, DNA sequencing, and glycosylation analyses will be employed to reconstruct the biomolecular organization of the glue from each species. This will be the first study to investigate the importance of glue gene length and repetitiveness for glue function, and the first comparison of posttranslational O-glycosylation modifications in a diversity of bioadhesives. Second, force transduction measurements during adhesive manipulation will allow documentation and analysis of the biomechanical properties of each glue. Combined with full-length sequences, direct inference will be made about the mechanical potential of glue sequence, including the role of repeat number and unit complexity in contributing to adhesive toughness and extensibility. Finally, we will reconstruct gene trees in order to evaluate support for parallel or convergent evolution of prey capture adhesives. Similar sequence identity will support the convergent strength of functional selection in the evolution of prey capture glue genes. Alternatively, poor sequence identity between glue transcripts indicates that a variety of biochemical mechanisms exist for prey adhesion, providing exciting novel pathways for biomimetic synthesis.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.