The changes of gene expression in honeybee (Apis mellifera) brains associated with ages.

Honeybee (Apis mellifera) worker bees (workers) are known to perform wide variety of tasks depending on their ages. The worker's brains also show the activity and behavior-dependent chemical and structural plasticity. To test if there are any changes of gene expression associated with different ages in the worker brains, we compared the gene expression patterns between the brains of newly emerged bees and old foraging workers (foragers) by macroarray analysis. The expression of genes encoding signal transduction pathway components, ion channels, and neurotransmitter transporters is elevated in the old forager brains, suggesting that the neuronal activities would be enhanced. The mRNA levels of cell adhesion protein, transcription related factors, and plasma membrane associated proteins are also increased in the old forager brains. Meanwhile, the mRNA level of one putative cell adhesion protein is decreased in the old forager brains. These results thus suggest that the dramatic changes of gene expression occur in honeybee brains associated with ages.