Genetic underpinnings of division of labor in the honeybee (Apis mellifera).

Honeybees have been studied for centuries, starting with Aristotle, who wrote the first book about bee breeding. More than 2000 years later, the honeybee entered the genomic era as the first social insect whose genome was sequenced, leading to significant insight into the molecular mechanisms underlying social behavior. In addition, gene expression studies and knockdown using RNAi have extended the understanding of social interactions. Much of the work has focused on caste determination - the mechanism that results in reproductive division of labor, division of labor within the worker caste, and worker reproduction - an essential process underlying eusociality. Here we review the molecular factors involved in caste determination and the differential regulation of caste-specific genes. Recent findings suggest that division of labor is influenced by a small number of loci showing high levels of pleiotropy, suggesting that changes in a small number of genes lead to large changes in the phenotype.