Allele specific expression in worker reproduction genes in the bumblebee Bombus terrestris

Genomic imprinting is the differential expression of alleles, with the expression being dependent upon the sex of the parent from which it was inherited. Hymenopteran insects (ants, bees and wasps) are emerging as potential models for genomic imprinting and epigenetics. As a first step in establishing the possibility of genomic imprinting in the bumblebee, Bombus terrestris, we search for allele specific expression in twelve genes associated with worker reproduction. We found that the patrigene (allele from the father) is more expressed than the matrigene (allele from the mother) in Ecdysone 20 monooxygenase. This enzyme catalyses the reaction which turns the ecdysteroid ecdysone into 20-hydroxyecdysone, also an ecdysteroid. Both of these ecdysteroids are important for worker reproduction in the bumblebee.