@article{ScheinerTotevaReimetal.2014,
  author    = {Scheiner, Ricarda and Toteva, Anna and Reim, Tina and Sovik, Eirik and Barron, Andrew B.},
  title     = {Differences in the phototaxis of pollen and nectar foraging honey bees are related to their octopamine brain titers},
  series = {Frontiers in physiology},
  volume    = {5},
  journal   = {Frontiers in physiology},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-042X},
  doi       = {10.3389/fphys.2014.00116},
  pages     = {8},
  year      = {2014},
  abstract  = {The biogenic amine octopamine is an important neuromodulator, neurohormone and neurotransmitter in insects. We here investigate the role of octopamine signaling in honey bee phototaxis. Our results show that groups of bees differ naturally in their phototaxis. Pollen forgers display a lower light responsiveness than nectar foragers. The lower phototaxis of pollen foragers coincides with higher octopamine titers in the optic lobes but is independent of octopamine receptor gene expression. Increasing octopamine brain titers reduces responsiveness to light, while tyramine application enhances phototaxis. These findings suggest an involvement of octopamine signaling in honey bee phototaxis and possibly division of labor, which is hypothesized to be based on individual differences in sensory responsiveness.},
  language  = {en}
}
@article{ThammScheiner2014,
  author    = {Thamm, Markus and Scheiner, Ricarda},
  title     = {PKG in honey bees: spatial expression, amfor gene expression, sucrose responsiveness, and division of labor},
  series = {The journal of comparative neurology},
  volume    = {522},
  journal   = {The journal of comparative neurology},
  number    = {8},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0021-9967},
  doi       = {10.1002/cne.23500},
  pages     = {1786 -- 1799},
  year      = {2014},
  abstract  = {Division of labor is a hallmark of social insects. In honey bees, division of labor involves transition of female workers from one task to the next. The most distinct tasks are nursing (providing food for the brood) and foraging (collecting pollen and nectar). The brain mechanisms regulating this form of behavioral plasticity have largely remained elusive. Recently, it was suggested that division of labor is based on nutrition-associated signaling pathways. One highly conserved gene associated with food-related behavior across species is the foraging gene, which encodes a cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG). Our analysis of this gene reveals the presence of alternative splicing in the honey bee. One isoform is expressed in the brain. Expression of this isoform is most pronounced in the mushroom bodies, the subesophageal ganglion, and the corpora allata. Division of labor and sucrose responsiveness in honey bees correlate significantly with foraging gene expression in distinct brain regions. Activating PKG selectively increases sucrose responsiveness in nurse bees to the level of foragers, whereas the same treatment does not affect responsiveness to light. These findings demonstrate a direct link between PKG signaling in distinct brain areas and division of labor. Furthermore, they demonstrate that the difference in sensory responsiveness between nurse bees and foragers can be compensated for by activating PKG. Our findings on the function of PKG in regulating specific sensory responsiveness and social organization offer valuable indications for the function of the cGMP/PKG pathway in many other insects and vertebrates. J. Comp. Neurol. 522:1786-1799, 2014. (c) 2013 Wiley Periodicals, Inc.},
  language  = {en}
}