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

一些无脊椎动物物种会产生捕获猎物的胶，这些胶沉积在丝上、分泌到四肢上或直接喷射到猎物上。这些胶水的干燥时间和对湿度的反应在材料上是独特的，但它们的功能相似，因为它们的粘度根据施加的力和快速粘合而变化。研究人员将研究三个远缘类群中 10 个物种的猎物捕获胶的分子和物理属性：蛛形纲动物（蜘蛛和阿皮林科动物）、苍蝇（掠食性萤火虫）和有甲虫（绒虫）。通过了解胶水性能相对于其分子基础的差异，可以为新型合成粘合剂的设计建立必要成分的目录。这项研究将进一步提高代表性不足的少数群体对实地课程作业的参与，研究继续证明，这对于选择生态学、进化和环境科学职业的个人至关重要。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”。本课程侧重于现场鉴定、标本采集和保存。带着进一步提高公众对阿巴拉契亚地区蜘蛛类动物的积极认知和兴趣，以及为不同学生群体提供实地考察机会的双重目标，研究人员将通过注重多样性的奖学金、新课程材料以及通过学生参与对哈佛商学院蜘蛛类动物收藏的贡献来支持学生出勤，从而增强现有课程。与在选择压力下多样化的同源来源材料不同，研究来自远缘相关生物的趋同进化的猎物捕获胶提供了一个独特的机会来探索必要的和新颖的用于构建这些粘合剂的组件。该项目将研究猎物捕获胶，其广泛目标是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，将采用靶向转录组学、DNA 测序和糖基化分析来重建每个物种胶的生物分子组织。这将是第一项研究胶基因长度和重复性对胶功能的重要性的研究，也是首次比较多种生物粘合剂中翻译后 O-糖基化修饰。其次，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，将直接推断出胶水序列的机械潜力，包括重复次数和单元复杂性在促进粘合剂韧性和延伸性方面的作用。最后，我们将重建基因树，以评估对猎物捕获粘合剂的并行或收敛进化的支持。相似的序列同一性将支持猎物捕获胶基因进化中功能选择的收敛强度。另外，胶水转录本之间较差的序列同一性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 NSF 的法定使命，并通过使用基金会的智力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.