Collaborative Research: Comparative analyses of structural designs underlying functional performance of the toughest spider silk

University Of Massachusetts Lowell, Lowell MA

Investigators

Abstract

Spider silks are the toughest materials in nature and hold immense promise to inspire a new generation of high-performance synthetic biomaterials. In the rainforests of Madagascar, Darwin's bark spider spins giant orb webs across rivers and lakes using a silk that is far tougher than silk produced by any other known spider. This project aims to understand how Darwin's bark spider produces such 'super' silk and how the silk functions in these giant webs. Through comparison to closely related species, the project will test how newly discovered spinning gland modifications and silk proteins found in Darwin's bark spider interact to produce super tough silk, and if those features are necessary to spin giant webs across rivers. Insight gained from these exceptional spiders will aid in the development of super-silk proteins that can inspire the design of new high-performance materials. Students and postdoctoral researchers will be trained to conduct interdisciplinary research, through direct participation in the project in the US and Madagascar, and through the development of curriculum for a variety of courses, including those offered by The University of Akron's Biomimicry Research and Innovation Center. Public outreach showcasing the natural history of these engaging spiders will provide a platform for linking the study of biodiversity to technological innovation. Such broader impacts will be achieved through an exhibit at the University of Vermont's Natural History Museum and educational activities for students in grades 5-9 at the Tsongas Industrial History Center at Lowell National Historical Park. This project will investigate silk production, structure and biomechanics among Darwin's bark spider (Caerostris darwini) and its close relatives in a comparative framework to determine the key design features underlying super-tough silk and how they evolved with web ecology. The objectives are to: 1) quantify the material properties of dragline fibers and kinematics of Caerostris webs; 2) characterize the structural proteins and spinning gland morphology that form Caerostris dragline silk; and 3) develop a robust Caerostris species phylogeny to infer the evolutionary causes and consequences of extremely tough silk. The work integrates genomic and proteomic analyses of silk proteins with functional characterization of silk threads and finite element modelling of web function and spider ecology. An evolutionary framework provided by phylogenomic analyses will test which traits facilitated the origin of super-tough silk and its implications for the evolution of giant spider webs.