eQTL mapping of hygienic behavior in honey bees

Honey bee (Apis mellifera) health continues to be threatened by a number of stressors, including the ectoparasitic mite Varroa destructor. Hygienic behavior, the detection, uncapping and removal of diseased brood, is one of several defenses that honey bees display against Varroa. However, the natural occurrence of this behavior is insufficient and needs to be improved by artificial selection and breeding programs. Phenotypic selection programs have proven effective but their long-term prospects may be improved by a better mechanistic understanding and additional marker identification. We used a cross between two novel honey bee strains that were selected for high and low hygienicity for a detailed analysis of the genetic architecture of hygienic behavior. Individuals were individually scored for hygienicity, genotyped by sequencing, and studied for head gene expression, including the transcriptome of brain and antennae. This combined “omics” approach allows us to investigate the relationship between the performance of hygienic behavior, gene expression differences, and the underlying genotypic variation. Our results will be compared to previous studies of hygienic behavior and discussed in the context of breeding programs and sustainable honey bee health.