Submitted to: Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: July 29, 2006
Publication Date: December 10, 2006
Citation: Yocum, G.D., Rinehart, J.P., Chirumamilla, A. 2006. Differential gene expression and respiration rates during the prediapause phase of the Colorado potato beetle, Leptinotarsa decemlineata [abstract]. Entomological Society of America. Paper No. D0429. p. 128. Technical Abstract: For an insect species to survive in any given geographic location, its life cycle must be tightly synchronized to all biotic and abiotic factors required for development and reproduction. Insects must also be able to survive predictable recurring periods of environmental stress, such as winter for temperate zone insects. Diapause is the chief physiological mechanism by which insects meet these two requirements for survival. Because of its central role enabling insect pests to survive and reproduce in a given area, an understanding of the mechanism of diapause is critical in the management of any agroecosystem. To clarify the molecular mechanism(s) regulating diapause initiation, prediapause Colorado potato beetles and those in early diapause were screened for diapause regulated genes. Using differential display 25 diapause-regulated genes were isolated. These genes fell within three broad classes: 1) genes expressed equally in both nondiapause controls and in prediapause beetles until day 7 of prediapause, followed by a sharp decrease in expression by day 20 of prediapause; 2) genes that increased in expression from days 1 to 7 of prediapause, with decreasing expression levels after day 7; and 3) Genes increasing in expression level after day 7 of prediapause. Respiration rates were determined in day 1 to day 15 prediapause and early diapause beetles. The beetles’ respiration rates decreased significantly after day 10 of prediapause and leveled off to very low levels by day 15 of prediapause. Comparing gene expression with respiration rates (overall metabolism) will provide insights into the timing of key events as the beetles are shutting down their normal metabolic activities and entering diapause for overwintering.