FBS Colloquia No.164Germline Biology Group

Molecular and neural bases that underlie honeybee social behaviors and their evolution

The honeybee is a social insect that lives forming a highly organized society and the workers inform their nestmates of the information regarding the food source using 'dance communication'. The molecular and neural bases of the brain, that underlie honeybee social behaviors, however, remain elusive. We have been performing comprehensive identification and analysis of genes expressed in a mushroom body (a higher-order center in the insect brain)-preferential manner in the honeybee brain. We found that the honeybee mushroom bodies comprise three types of Kenyon cells: in addition to the previously identified large- and small-type Kenyon cells, novel 'middle-type' Kenyon cells, that have distinct gene expression profiles. Neural activity mapping using immediate early genes revealed that both small-type Kenyon cells and a part of 'middle-type' Kenyon cells are active in forager brains, suggesting the role of these Kenyon cell subtypes in sensory information processing during the foraging flight. We are now performing functional analysis of these genes using genome-editing method, that we have recently established in the honeybee. Finally, I would like to talk about our new findings that the variety of Kenyon cell subtypes increased during the evolution of Hymenopteran insects.