The tale of three honey bees: Comparative genomics in the genus Apis

The genus Apis is comprised of about 10 different species of honey bees that belong to three clades. While all honey bees share many important biological features, such as their eusocial organization, their reproductive mode, foraging biology, and high recombination rates, the three clades differ in important other aspects, including the divergence between the non-reproductive worker caste and the reproductive queen caste. The availability of the genomes of Apis florea, representing the dwarf honey bee clade, and Apis dorsata, representing the giant honey bee clade, in addition to the established Apis mellifera genome now allows for the comparative study of honey bee genomes. We perform such analyses to identify honey bee specific genome features that have been conserved during the differentiation of the separate taxa and to characterize differences within this genus. Specifically, we discuss the evidence for selection in candidate genes that were identified by QTL mapping experiments for worker ovary size, which is an important aspect of caste divergence and honey bee social evolution.