The effect of diet on the composition and evolution of venom
Animal venoms are complex cocktails of bioactive polypeptides, known as toxins, that achieve their primarily defensive of predatory functions by potently and selectively targeting important physiological processes in their victims. As such, they have attracted significant attention as rich sources of novel compounds with potential use as human therapeutics, agrochemicals, and molecular tools. Venom is also among the most common independently evolved adaptive traits known among animals, with over 100 venomous animal lineages having evolved their own biochemical arsenal of toxins through the modification of existing “housekeeping” proteins and peptides. This rampant convergence has led to the emergence of venom as model traits for studying adaptive evolution and evolutionary innovation and novelty.
This project will, for the first time, experimentally test how a predatory venom responds to strong selection arising from changes in diet, using the common green lacewing Chrysoperla carnea as a model species. C. carnea is easily bred in the lab, but the larvae show marked differences in growth and survival depending on the composition of prey they are raised on. This provides an excellent opportunity to study how the evolution of venomous predators are affected by strong prey-induced selection pressure.
The project takes a multidisciplinary approach to examine diet-induced changes in venom composition in C. carnea (common green lacewing). The student will use a combination of comparative transcriptomics and proteomics of milked venom to examine changes in composition of venoms of larvae raised on different prey types, and use toxicity assays and comparative morphology to investigate any associated changes in venom system. Due to the short generation time of C. carnea, the student will also be able to monitor the effects of prey across multiple generations. This will yield new insight into the plasticity and adaptive potential of one of the most convergent animal traits known, and potentially lead to the identification of novel agrochemical leads.