Developmental Delays During Puberty in the Insect Manduca sexta Appear to Provide Sufficient Time to Maintain Body Allometry in Adults
Joana Navarro, Malea Tuimavave, Gurleen Kaur, Leslie Flores
Department of Biology
Faculty Supervisor: Megumi Fuse
Developmental delays arise during puberty in children with some diseases such as cystic fibrosis and diabetes, that may be compensatory mechanisms for dealing with tissue inflammation, but can have long term effects on reproduction. Insects have a “pubertal” stage that likewise delays after tissue damage. We use the model Manduca sexta to determine whether the delays provide a compensatory period for tissue regeneration. To assess this, we looked at body allometry - the proper proportioning of body parts - in adults after regeneration of damaged pre-pubertal (larval) tissue. M. sexta were exposed to radiation ranging from 25 to 75 Gray during the fifth larval stage to selectively damage tissues committed to becoming adult structure such as wings. We analyzed the allometry of the insect by measuring (i) the average area and perimeter of fore and hind wings and the whole body, (ii) the ratio of fore and hind wings relative to the whole body, and (iii) whole animal weight. Results showed no significant differences in body allometry in larvae damage by radiation at 25 and 50 Gy, compared to controls, indicating that radiation exposure did not affect appendage measurement. Some significant differences at 75 Gy suggest that full repair at this high dose is not always possible. This research contributes to our understanding of the mechanisms underlying organismal growth and regeneration.