The Effects of Radiation-Induced Imaginal Disc Damage on Wing Allometry in the Tobacco Hornworm, Manduca sexta
By: Leslie Flores
Department: Biology
Faculty Advisor: Dr. Megumi Fuse
The relationship between the size of an organism's appendages in comparison to the size of the rest of the body is known as allometry. Organisms must maintain proper proportions in order to best survive. Literature has shown that selectively damaging tissues can result in delayed development in the hornworm, Manduca sexta theoretically to provide time for tissue regeneration. This organism can therefore be used as a model to understand the effects of tissue damage on allometry in general. It is not clear, however, how well these tissues regenerate, and whether body allometry is maintained. I investigated the correlation between cell and tissue regeneration following tissue damage. Wing socket cells were analyzed after phalloidin staining, from larvae whose wing imaginal discs were selectively damaged by irradiation. Subjects had received different irradiation doses (25-75 Grey) and were allowed to develop into moths prior to staining with phalloidin, an actin filament-specific fluorescent stain. In this study, cell area, perimeter, and count were analyzed from the fluorescent images using the image processing software, ImageJ. No significant differences were found for the overall average area, perimeter, or cell count between the control and irradiated groups. This suggests that tissue regeneration was successful during the damage-induced extended developmental period, where cell size and count were not affected. To gain further insights, whole wing samples and other appendages that arose from damaged imaginal discs are being measured.