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United States Department of Agriculture

Agricultural Research Service

Research Project: INSECT CRYOPRESERVATION, DORMANCY, GENETICS AND BIOCHEMISTRY

Location: Insect Genetics and Biochemistry Research

Title: Transcriptome profiling of diapause and post-diapause quiescent alfalfa leafcutting bees

Authors
item Yocum, George
item Rinehart, Joseph
item Horvath, David
item Kemp, William

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 18, 2012
Publication Date: November 11, 2012
Citation: Yocum, G.D., Rinehart, J.P., Horvath, D.P., Kemp, W.P. 2012. Transcriptome profiling of diapause and post-diapause quiescent alfalfa leafcutting bees. Meeting Abstract. Paper No. D0253.

Interpretive Summary: The alfalfa leafcutting bee, Megachile rotundata is used to pollinate various crops in North and South America and Europe. In terms of the number used annually and hectares of crops pollinated, M. rotundata is the most intensely managed solitary bee species used in managed pollination programs. A key component in M. rotundata management programs is overwintering storage of the bees. Megachile rotundata overwinters up to nine months of the year in a state of dormancy known as diapause. Thus, improving our understanding of diapause physiology in M. rotundata will yield benefits including healthier, more vigorous pollinator populations that could greatly expand the use of this solitary bee. One possible means of achieving this goal would be the identification of molecular biomarkers related to diapause and post diapause development. Currently very little is known about the molecular regulation of insect diapause in general and even less is known about regulation of M. rotundata diapause. Using Illumina sequencing, 1222 diapause-regulated genes were identified. These genes are associated with key metabolic and regulatory pathways. These genes will be employed as molecular biomarkers to improve the M. rotundata husbandry.

Technical Abstract: The alfalfa leafcutting bee, Megachile rotundata is used to pollinate various crops in North and South America and Europe. In terms of the number used annually and hectares of crops pollinated M. rotundata is the most intensely managed solitary bee species used in managed pollination programs. A key component in M. rotundata management programs is overwintering storage of the bees. Megachile rotundata overwinters as diapausing prepupae, therefore understanding the physiology of M. rotundata will provide new insights for improving the management of this key pollinator. Currently very little is known about the molecular regulation of insect diapause in general and even less is known about regulation of M. rotundata diapause. In this investigation, Illumina sequencing was employed to examine the physiological transition from diapause to post-diapause development. Illumina identified 1222 differentially regulated genes, 316 of the genes were downregulated and 906 were upregulated in the post-diapausing prepupae. KEGG pathway analysis revealed that the top three associated pathways with the diapause upregulated genes are starch and sucrose metabolism, glycolysis / gluconeogenesis and purine metabolism and for diapause downregulated genes the top three pathways are purine metabolism, pyrimidine metabolism, and phosphatidylinositol signaling system.

Last Modified: 12/18/2014
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