Regulation of allometric growth after imaginal disc damage in the tobacco hornworm, Manduca sexta


Meeting Abstract

P2-42  Friday, Jan. 5 15:30 – 17:30  Regulation of allometric growth after imaginal disc damage in the tobacco hornworm, Manduca sexta ZAVALETA, J/A*; ROSERO, M; FUSE, M; San Francisco State University jhony.zavaleta@gmail.com

Experiments in Manduca sexta and other holometabolous insects have shown that damage to imaginal tissues at early larval stages delays the onset of metamorphosis. These delays in development are assumed to be the result of a mechanism to allow for regeneration of the damaged tissues and regulation of growth of undamaged ones. Putatively, this regulation of growth, known as body allometry, ensures that the recovered animals develop into adults with properly scaled bodies. It is not known, however, if these assumptions are true that developmental delays allow organisms to conserve their body allometry. Therefore, we have hypothesized that the observed delays in development are the result of a mechanism designed to conserved the body allometry of an organism despite damage to progenitor tissues. In this particular study we assessed changes in the body allometry of M. sexta after varying levels of damage to its imaginal discs via different doses of X-ray radiation to selectively damage imaginal discs. We then tracked recovering animals until adulthood, at which point we measured the growth rate of various appendages in comparison to the body and used these measurements to determine the scaling factor and allometric coefficient by means of a standard major axis (SMA) linear regression. Preliminary data suggests little to no variation in the scaling factor or allometric coefficient at low doses. We will then discuss in detail the extent at which body allometry was conserved with respect to the adult’s appendages and what this could imply toward the regulation of the developmental checkpoints in the animal.

the Society for
Integrative &
Comparative
Biology