Meeting Abstract
Visual systems are complex and require that all pieces work together to form clear images. The refractive power of the lens is fundamentally important for any eye to maintain correct focusing. During growth, all parts of the eye need to coordinate to maintain focus. Previous studies have thoroughly examined how vertebrates can preserve this property during their growth, but there are few studies which attempt to answer the question in invertebrates. Unlike vertebrates which grow gradually, insects must undergo ecdysis—shed their outer layer, including their lenses. This presents a unique evolutionary challenge to overcome: how do you maintain correct focus with rapid eye growth? An excellent model for eye development are Thermonectus marmoratus larvae which have exceptional eyes that use a bifocal lens to focus images on two retinas. These larvae undergo rapid growth between their 2nd and 3rd larval stages and substantially reform their lenses to accommodate this growth. The cuticular protein Lens3 is a major contributor to the lens. In this project we use RNAi to knock down Lens3 expression and to investigate if reduction of this major lens protein leads to refractive errors, or if T. marmoratus eye development contains compensatory mechanisms that allow correct focus to be maintained. Knockdowns can be measured using a customized ophthalmoscope to determine focusing abilities. This study will provide insights towards the question of whether invertebrates use active or passive regulation to maintain focus.
