Identification of proteins whose expression is up- or down-regulated in the mushroom bodies in the honeybee brain using proteomics

To identify protein(s) with different expression patterns in the mushroom bodies (MBs) in the honeybee brain, we compared the protein profiles of MBs and optic lobes (OLs) using proteomics. Two-dimensional gel electrophoresis revealed that five and three spots were selectively expressed in the MBs or OLs, respectively. Liquid chromatography tandem mass spectrometry analysis identified juvenile hormone diol kinase and glyceraldehyde-3-phosphate dehydrogenase as MB- and OL-selective proteins, respectively. In situ hybridization revealed that jhdk expression was upregulated in MB neuron subsets, whereas gapdh expression was downregulated, indicating that MBs have a distinct gene and protein expression profile in the honeybee brain.