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

有几类无脊椎动物会产生捕食胶，这些胶会沉积在丝绸上，分泌到四肢上，或者直接喷到猎物身上。这些胶水的干燥时间和对湿度的反应在材料上是独一无二的，但它们在功能上是相似的，因为它们的粘度根据施加的力和快速粘合而变化。研究人员将调查来自三个远亲群体的10个物种的捕食胶的分子和物理属性-蜘蛛类(蜘蛛和眼镜蛇)、苍蝇(捕食性荧光虫)和指甲虫(天鹅绒蠕虫)。通过了解胶水性质与其分子基础的差异，可以为设计新的合成胶粘剂建立必要的成分目录。这项研究将进一步促进未被充分代表的少数群体参与实地课程工作，研究继续表明，这对选择生态、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野外课程--蜘蛛生物学。这门课的重点是野外鉴定、标本采集和保存。为了促进公众对阿巴拉契亚地区蜘蛛类的积极认知和兴趣，以及改善不同学生群体获得实地考察的机会，研究人员将通过注重多样性的奖学金、新的课程材料和通过学生参与为哈佛商学院蜘蛛类收藏做出贡献来支持学生参加现有课程。与具有同源来源的材料在选择压力下多样化不同，研究从远亲生物中一致进化的猎物捕获胶为探索构建这些粘合剂的必要和新颖的成分提供了一个独特的机会。这个项目将研究捕食胶，其广泛的目标是了解它们的分子成分对功能的贡献，并发现与功能、生态或形态相似相关的共性。首先，将使用定向转录、DNA测序和糖基化分析来重建每个物种的胶水的生物分子组织。这将是第一次研究胶基因长度和重复性对胶功能的重要性，也是第一次比较不同生物粘合剂中翻译后O-糖基化修饰的情况。其次，粘合剂操作过程中的力传递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，将直接推断胶水序列的力学潜力，包括重复数和单位复杂性在促进粘接韧性和延展性方面的作用。最后，我们将重建基因树，以评估对捕食粘合剂并行或收敛进化的支持。相似的序列同源性将支持功能选择在猎物捕获胶基因进化中的收敛强度。或者，胶水转录本之间较差的序列一致性表明，存在多种用于猎物黏附的生化机制，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优势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.