The Effects of Larval Wing Disc Tissue Damage in The Hornworm, Manduca sexta, on the Symmetry of Wing Development
By: Andrea Silva
Department: Biology
Faculty Advisor: Dr. Megumi Fuse
Maintaining body allometry is a mechanism to ensure an organism’s survival in their specific environmental niches but is also important for proper physiological functioning. Research has suggested that events causing tissue damage in the hornworm, Manduca sexta, lead to delays in development to putatively provide time for tissue regeneration to maintain body allometry. Thus, this organism is a useful model for understanding tissue repair and the importance of body allometry. How body proportions are maintained during this regeneration, however, is unclear. An expected outcome would show significant differences in tissue repair between control and affected insect groups, and possibly even asymmetrical changes within an animal. To test this, M. sexta larval wing imaginal tissues were damaged via irradiation and animals were then analyzed throughout their life stages until becoming adults. Wing socket cells were then stained and counted and measured for area and perimeter using ImageJ software. The absolute difference in the left- and right-wing data was then calculated to determine whether any asymmetric effects arose during tissue regeneration. The difference for cell area and perimeter (for both left and right wings) did show differences for the irradiated groups, although currently, the data is too small for appropriate statistical testing. Nevertheless, it suggests that the effects of tissue damage may result in some asymmetric tissue regeneration. This suggests that developmental timing was affected, and not enough healthy tissue was generated once animals reached adulthood.