Abundance of phosphorylated Apis mellifera CREB in the honeybee's mushroom body inner compact cells varies with age.
Hymenopteran eusociality has been proposed to be associated with the activity of the transcription factor CREB (cAMP-response element binding protein). The honeybee (Apis mellifera) is a eusocial insect displaying a pronounced age-dependent division of labor. In honeybee brains, CREB-dependent genes are regulated in an age-dependent manner, indicating that there might be a role for neuronal honeybee CREB (Apis mellifera CREB, or AmCREB) in the bee's division of labor. In this study, we further explore this hypothesis by asking where in the honeybee brain AmCREB-dependent processes might take place and whether they vary with age in these brain regions. CREB is activated following phosphorylation at a conserved serine residue. An increase of phosphorylated CREB is therefore regarded as an indicator of CREB-dependent transcriptional activation. Thus, we here examine the localization of phosphorylated AmCREB (pAmCREB) in the brain and its age-dependent variability. We report prominent pAmCREB staining in a subpopulation of intrinsic neurons of the mushroom bodies. In these neurons, the inner compact cells (IC), pAmCREB is located in the nuclei, axons, and dendrites. In the central bee brain, the IC somata and their dendritic region, we observed an age-dependent increase of pAmCREB. Our results demonstrate the IC to be candidate neurons involved in age-dependent division of labor. We hypothesize that the IC display a high level of CREB-dependent transcription that might be related to neuronal and behavioral plasticity underlying a bee's foraging behavior.
Institute for Biology-Neurobiology, Freie Universität Berlin, D-14195, Berlin, Germany.
Katrin B
KB
Gehring
Institute for Biology-Neurobiology, Freie Universität Berlin, D-14195, Berlin, Germany.
Karin
K
Heufelder
Institute for Biology-Neurobiology, Freie Universität Berlin, D-14195, Berlin, Germany.
Isabella
I
Kersting
Institute for Biology-Neurobiology, Freie Universität Berlin, D-14195, Berlin, Germany.
Dorothea
D
Eisenhardt
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D001516:Bees; D002645:Chickens; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D004330:Drosophila; D006801:Humans; D024521:Mushroom Bodies / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D010766:Phosphorylation / Q000502:physiology
D017362:Cyclic AMP Response Element-Binding Protein
AB_212802; AB_2313867; AB_557403; CREB; RRIDs: AB_2085876; age; brain; division of labor; honeybee; inner compact cells; mushroom body