11/26/2024
By Irma Silva
Date: Wednesday, Dec. 11
Time: 3:30 – 5:30 p.m.
Location: Olsen Hall 114
Committee Members:
Frederick Chain, Associate Professor, UMass Lowell
Jessica Garb, Associate Professor, UMass Lowell
Liam Revell, Professor of Biology, UMass Boston
Sandra Correa-Garhwal, Assistant Professor of Biology, Suffolk University
Abstract:
Spiders in the family Uloboridae construct unusual web forms including horizontal, vertical, and reduced orb webs with varying degrees of modified architecture. The most extreme examples include the triangle-weavers (genus Hyptiotes), which spring-loads its web and slingshots forward to ensnare its victim and the genus Miagrammopes, which uses a single silk line of dragline wrapped in capture silk to catch prey. Spider silk fibers are composed of large, repetitive proteins (spidroins), which determine the mechanical properties of the silk they compose. The spidroin structure-function relationship has been well characterized in orb-weaving spiders known as ecribellate orb-weavers, thought to have particularly tough dragline to support their large webs. By contrast silk molecular composition and mechanical performance in the distantly related cribellate orb weavers (Uloboridae), is virtually unstudied. This gap in knowledge represents an opportunity to uncover how evolution has modified silk proteins to meet unusual mechanical demands, enabling species to occupy new ecological niches, and potentially reveal novel insight into structure function relationships required for designing optimal biomaterials. For my thesis, I propose to investigate the relationship between dragline silk molecular structure, mechanical properties, and web form in Uloboridae, focusing on silk evolution in heavily modified webs. This will employ the use of genomic and transcriptomic data, phylogenetic comparative methods, and direct mechanical testing of dragline fibers. Specifically, I will evaluate whether web reduction is correlated with a dragline gene modification in Uloboridae, and I will relate dragline silk structure and composition to its mechanical performance, comparing with existing data from well-studied spider families.