Department of Biology, Vassar College, Poughkeepsie, NY 12604-0731, USA.
Division of Invertebrate Zoology and Institute for Comparative Genomics, American Museum of Natural History, New York, NY 10024, USA.
J Exp Biol. 2022 Feb 15;225(Suppl1). doi: 10.1242/jeb.243271. Epub 2022 Feb 4.
Morphological structures and extended phenotypes are made possible by materials that are encoded by the genome. Nearly all biomaterials are viscoelastic, which means that to understand performance, one must understand the strain rate-dependent properties of these materials in relevant ecological interactions, as the behavior of a material can vary dramatically and rapidly. Spider silks are an example of materials whose properties vary substantially intra- and inter-specifically. Here, we focus on aggregate silk, which functions as a biological adhesive. As a case study to understand how a material manifests from genome through organism to ecology, we highlight moth-specialist spiders, the Cyrtarachninae, and their glues as an ideal experimental system to investigate the relationship between genomics and ecologically variable performance of a biological material. There is a clear eco-evolutionary innovation that Cyrtarachne akirai and related species have evolved, a unique trait not found in other spiders, a glue which overcomes the scales of moths. By examining traditional orb-weavers, C. akirai and other subfamily members using biomechanical testing and genomic analysis, we argue that we can track the evolution of this novel bioadhesive and comment on the selection pressures influencing prey specialization. The importance of the ecological context of materials testing is exemplified by the poor performance of C. akirai glue on glass and the exceptional spreading ability and adhesive strength on moths. The genetic basis for these performance properties is experimentally tractable because spider silk genes are minimally pleiotropic and advances in genomic technologies now make possible the discovery of complete silk gene sequences.
形态结构和扩展表型是由基因组编码的材料所实现的。几乎所有的生物材料都是粘弹性的，这意味着为了理解性能，人们必须理解这些材料在相关生态相互作用中的应变率依赖性特性，因为材料的行为可能会发生巨大而迅速的变化。蜘蛛丝就是一个材料性能在种内和种间都有很大差异的例子。在这里，我们专注于聚合丝，它作为一种生物粘合剂发挥作用。作为一个案例研究，以了解材料如何从基因组通过生物体到生态系统表现出来，我们强调了以蛾类为食的蜘蛛，即 Cyrtarachninae 及其胶作为一个理想的实验系统，以研究基因组学和生物材料的生态变化性能之间的关系。有一个明显的生态进化创新，即 Cyrtarachne akirai 和相关物种已经进化出一种独特的特性，这种特性在其他蜘蛛中是找不到的，一种可以克服蛾类鳞片的胶。通过对传统圆网蜘蛛、C. akirai 和其他亚科成员进行生物力学测试和基因组分析，我们认为我们可以追踪这种新型生物粘合剂的进化，并对影响猎物特化的选择压力进行评论。材料测试的生态背景的重要性可以通过 C. akirai 胶在玻璃上的性能不佳以及在蛾类上的出色扩展能力和粘附强度得到例证。这些性能特性的遗传基础是可以通过实验来追踪的，因为蜘蛛丝基因的多效性很小，并且基因组技术的进步使得发现完整的丝基因序列成为可能。
