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United States Department of Agriculture

Agricultural Research Service

Research Project: INSECT GENOMIC BIODIVERSITY AND MOLECULAR REGULATION OF DIAPAUSE Title: Changes in Respiratory Quotient and Gene Expression in Megachile Rotundata Prepupae During the Transition from Diapause to Postdiapause at a Constant 4°c

item Yocum, George
item Kemp, William
item Knoblett, Joyce

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 20, 2006
Publication Date: May 20, 2006
Citation: Yocum, G.D., Kemp, W.P., Bosch, J., Knoblett, J.N. 2006. Changes in respiratory quotient and gene expression in Megachile rotundata prepupae during the transition from diapause to postdiapause at a constant 4 deg. C. [abstract]. 5th International Symposium on Molecular Insect Science. p. 93.

Technical Abstract: Predicting pest emergence dates and forecasting crop damage levels require knowledge of the diapause termination date. This varies regionally and yearly based on environmental conditions. Similarly, synchronizing the emergence of managed pollinating solitary bees with the peak bloom of target crops is central for developing these pollinators in North America. To better understand diapause termination in M. rotundata in order to predict termination date and post diapause development under field conditions, and to be able to manipulate the termination date to match the bees’ emergence with the peak bloom of target crops, we initiated a series of investigations. In the first study, we examined gene expression and respiration patterns in field maintained bees. This study demonstrated that there is no sudden transition between diapause and post diapause development. Because of the complexity of multiple variables in field experiments, we next asked the question, “Can a simple constant low temperature treatment be used to accurately model gene expression and respiration patterns of field maintained insects?” The results of current investigation indicate that the level of gene expression for selected genes in diapausing and post-diapause bees is highly influenced by their thermal history. Based on our observations of the prolonged elevated levels of HSP70 expression and differences in expression patterns of HSP90, HSC70 and actin as compared to field collected bees we conclude the following: 1) A constant low-temperature regime is not an accurate model for gene expression and respiration patterns of field-collected insects; 2) Examining diapause development at several levels (e.g., organismal and molecular) and under different environmental regimes will allow us to tease apart the different components of diapause development.

Last Modified: 4/22/2015
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