Behavioral and genetic correlates of heterogeneity in learning performance in individual honeybees, Apis mellifera

Abstract

Learning an olfactory discrimination task leads to heterogeneous results in honeybees with bees performing very well and others at low rates. Here we investigated this behavioral heterogeneity and asked whether it is associated with particular gene expression patterns. Bees were individually conditioned in a sequential conditioning protocol involving several phases of olfactory learning and retention tests. The rate of CS+ odor learning was found to correlate highest with a cumulative performance score extracted from all learning and retention tests. The cumulative score was used to sort the tested bees into high and low performers. Microarray analysis of gene expression in the mushroom body area of the brains of these bees disclosed a list of genes, which were differentially expressed between the high and low performers. These candidate genes are implicated in diverse biological functions, such as neurotransmission, memory formation, cargo trafficking and development.