Colonies of haplodiploid Hymenopteran insects serve as model systems for examining how cooperative behaviour can evolve. More recently, insect colonies have emerged as important systems for understanding within-genome conflict.In eusocial species such as honey bees, queens are polyandrous and mate early in life with 10-20 males. The queen stores the spermatozoa of each drone in an organ known as the spermatheca, and utilises this sperm to fertilize queen- or worker-destined eggs. Honey bee colonies are therefore comprised of subfamilies of workers each of which share the same father. This generates the potential for conflict between males to increase the reproductive success of their female offspring. A father able to influence the expression of genes in offspring, so his daughters are more likely to develop as a queen or a reproductive worker, has a greater probability of reproductive success than another male that fails to do so. Recently, genes that influence worker reproduction have been found to have paternally-biased expression. That is the allele derived from the father is expressed whereas the maternal allele is switched off. This suggests reproductive conflict between the paternal and maternal genomes of females. The mechanism that influences this paternal bias remains unknown, but DNA methylation has been proposed as the most likely.To identify the genes modified by fathers and the mechanisms underlying differentially expressed genes, we generated replicate reciprocal crosses between two African honey bee subspecies. We then sequenced both parents (whole-genome) and offspring (transcriptome and methylome). The current findings will be discussed