Submitted to: National Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 10/29/2003
Publication Date: 1/5/2004
Citation: Gelman, D.B., Margam, V.M., Palli, S.R. 2004. Tcaiii is not required for photorhabdus luminescens toxin complex a's toxicity against adult silverleaf whiteflies (bemisia tabaci strain b). National Entomological Society of America Annual Meeting. November 14-17,2004 Abstract avail. online Interpretive Summary:
Technical Abstract: Ecdysteroids play crucial roles in insect developmental processes, including molting, metamorphosis and reproduction. We are interested in studying the regulation of molting and metamorphosis by ecdysteroids during the development of the yellow fever mosquito, Aedes aegypti. As a first step towards this goal, we determined the ecdysteroid fluctuations during the final larval instar and during the pupal stage of this insect. Fourth instar larvae and pupae were collected at 0 hr and then at 6 hr intervals. Ecdysteroid titers of whole body extracts were determined using a radioimmnoassay. In fourth instars, two major peaks of ecdysteroids were observed, one at 24 hr and one at 48 hr. In pupae, there was a single ecdysteroid peak. It occurred at 6-12 hr after the larval-pupal molt. Northern blot and quantitative reverse transcriptase polymerase chain reaction analysis of expression of genes (EcR, usp, E75 and HR3) associated with the ecdysteroid signal cascade is in progress. These data will help to elucidate the relationship between gene action and the ecdysteroid peaks observed during the final larval instar and pupal stage of A aegypti.