Silk is one of nature’s strongest and lightest biomaterials. It is used by hundreds of thousands of species for an array of applications. Yet, outside of a few species, little is known about the genomic basis and material properties of natural silks. This project takes an integrative approach to examine the molecular, developmental, and functional basis of silk across a diversity of uses. An integrative team of natural historians, molecular biologists, developmental biologists, and bioengineers are combining their expertise to gain insight into how nature shapes silk fiber function. This research is foundational to engineering new materials that can applied to many products, from surgical adhesives to sustainable clothing. As part of this project, multiple postdoctoral researchers and graduate students gain interdisciplinary training in genomics, gene editing, and engineering. Furthermore, this project creates a traveling museum exhibit to educate the public about the natural properties of silk.<br/><br/>Silk has been shaped and re-adapted for an extraordinary diversity of uses across multiple distantly related arthropod groups and hundreds of millions of years of evolution. To date, silk research in insects has focused largely on fibers from the domesticated silkworm moth, Bombyx mori. This project uses a comparative, multi-tiered approach to study silks of the most dominant clade of silk-producing insects, the caddisflies and moths. The combination of genomics, proteomics, functional genetics, and biophysical measurements will illuminate how silks adhere to underwater substrates, how they consolidate into an insoluble fiber, and help understand the molecular basis of their mechanical properties. Evolutionary correlations are woven between genotypes and phenotypes and direct tests of causality are conducted in strategically chosen focal species that are amenable to genetic modification. Overall, this project addresses the overarching question, “How does nature shape silk fiber function?” with a new framework for a fundamental biological superstructure that has untapped potential for the production of new polymer-based biomaterials.<br/><br/>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.