Detoxification genes and their expression levels in different life stages of bumble bee (Bombus huntii)

Bumble bees (Bombus huntii) play an important role as pollinators of crops and other plants.  However, they get exposed to toxic substances in the environments, such as insecticides and plant toxins, during pollination activities. We developed a cDNA database of 102,778 contigs and singlets using pyrosequencing of mRNA extracted from eggs, larvae, pupae, workers, drones, an egglaying queen, and a diapausing queen of the western bumble bee. Approximately 1500 detoxification genes known from other insects were found to be expressed in this bee, such as genes coding for cytochrome P450s, catalase, CuZn superoxide dismutase, peroxidase,  glutathione-S-transferase-like protein, carboxylesterase,  esterases and lipase. The expression levels of these genes varied significantly among the different life stages of the bee, as determined using the RNA-seq analyses.  Although the number of detoxification mechanisms are reduced in males and late instar larval workers, some of the genes that are expressed are more highly expressed than in the adult females (adult workers and queens).