Meeting Abstract
Holometabolous insects undergo radical body changes from larvae through adulthood, which has allowed them to increase their range of geographic niches. Many of the adult structures arise from highly proliferating stem cell-like primordial tissues, called imaginal discs. When damaged, they affect extended larval and pupal development. This is assumed to provide time for regeneration. However, it has not yet been verified the delays are a result of imaginal disc damage or undocumented damage to other tissues. We hypothesized the damage to disc tissue was the main factor contributing to developmental delays and developed a transplant method to compare the effects of transplanting irradiated (damaged) discs into healthy larvae with the goal of delaying development. We transplanted irradiated and non-irradiated discs into healthy larvae with and without removing their original discs and monitored developmental timing. Removing the original discs appeared to be very traumatic, masking the effects of damage incurred via irradiation. That is, larvae receiving transplants – regardless of damage status – showed delays to pupation that were close to delays in irradiated controls. The delays were longest to the adult stage in transplanted animals – even longer than irradiated controls. These data indicate that the mechanical action of removing a recipient’s discs and inserting discs from a donor, whether or not the donor was irradiated, caused developmental delays. Preliminary results on effects of transplants into recipient animals that still have their original discs suggests that irradiated disc insertion delays development more than the insertion of non-irradiated discs. If these results are confirmed, then we have a useful method for assessing the role of damaged discs in regulating development, and can begin to assess the effects of different levels of radiation damage on development.
