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Genes related to immunity, as expressed in the alfalfa leafcutting bee, Megachile rotundata, during pathogen challenge


  • First published online 22 October 2009.

Rosalind James, USDA-ARS, Pollinating Insects Research Unit, Department of Biology UMC 5310, Utah State University, Logan, UT 84322-5310, USA. Tel: +1 435 797 0530; fax: +1 435 797 0461; e-mail:


Virtually nothing is known about disease resistance in solitary bees, so expressed sequence tag (EST) databases were developed to search for immune response genes in the alfalfa leafcutting bee. We identified 104 putative immunity-related genes from both healthy and pathogen-challenged bee larvae, and 12 more genes using PCR amplification. The genes identified coded for proteins with a wide variety of innate immune response functions, including pathogen recognition, phagocytosis, the prophenoloxidase cascade, melanization, coagulation and several signalling pathways. Some immune response genes were highly conserved with honey bee genes, and more distantly related to other insects. The data presented provides the first analysis of immune function in a solitary bee and provides a foundation for the further analysis of gene expression patterns in bees.