@article{ReimThammRolkeetal.2013,
  author    = {Reim, Tina and Thamm, Markus and Rolke, Daniel and Blenau, Wolfgang and Scheiner, Ricarda},
  title     = {Suitability of three common reference genes for quantitative real-time PCR in honey bees},
  series = {Apidologie : a quality journal in bee science},
  volume    = {44},
  journal   = {Apidologie : a quality journal in bee science},
  number    = {3},
  publisher = {Springer},
  address   = {Paris},
  issn      = {0044-8435},
  doi       = {10.1007/s13592-012-0184-3},
  pages     = {342 -- 350},
  year      = {2013},
  abstract  = {Honey bees are important model organisms for neurobiology, because they display a large array of behaviors. To link behavior with individual gene function, quantitative polymerase chain reaction is frequently used. Comparing gene expression of different individuals requires data normalization using adequate reference genes. These should ideally be expressed stably throughout lifetime. Unfortunately, this is frequently not the case. We studied how well three commonly used reference genes are suited for this purpose and measured gene expression in the brains of honey bees differing in age and social role. Although rpl32 is used most frequently, it only remains stable in expression between newly emerged bees, nurse-aged bees, and pollen foragers but shows a peak at the age of 12 days. The genes gapdh and ef1 alpha-f1, in contrast, are expressed stably in the brain throughout all age groups except newly emerged bees. According to stability software, gapdh was expressed most stably, followed by rpl32 and ef1 alpha-f1.},
  language  = {en}
}
@article{ReimScheiner2014,
  author    = {Reim, Tina and Scheiner, Ricarda},
  title     = {Division of labour in honey bees: age- and task-related changes in the expression of octopamine receptor genes},
  series = {Insect molecular biology},
  volume    = {23},
  journal   = {Insect molecular biology},
  number    = {6},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0962-1075},
  doi       = {10.1111/imb.12130},
  pages     = {833 -- 841},
  year      = {2014},
  abstract  = {The honey bee (Apis melliferaL.) has developed into an important ethological model organism for social behaviour and behavioural plasticity. Bees perform a complex age-dependent division of labour with the most pronounced behavioural differences occurring between in-hive bees and foragers. Whereas nurse bees, for example, stay inside the hive and provide the larvae with food, foragers leave the hive to collect pollen and nectar for the entire colony. The biogenic amine octopamine appears to play a major role in division of labour but the molecular mechanisms involved are unknown. We here investigated the role of two characterized octopamine receptors in honey bee division of labour. AmOctR1 codes for a Ca2+-linked octopamine receptor. AmOctR3/4 codes for a cyclic adenosine monophosphate-coupled octopamine receptor. Messenger RNA expression of AmOctR1 in different brain neuropils correlates with social task, whereas expression of AmOctR3/4 changes with age rather than with social role per se. Our results for the first time link the regulatory role of octopamine in division of labour to specific receptors and brain regions. They are an important step forward in our understanding of complex behavioural organization in social groups.},
  language  = {en}
}
@article{Scheiner2012,
  author    = {Scheiner, Ricarda},
  title     = {Birth weight and sucrose responsiveness predict cognitive skills of honeybee foragers},
  series = {Animal behaviour},
  volume    = {84},
  journal   = {Animal behaviour},
  number    = {2},
  publisher = {Elsevier},
  address   = {London},
  issn      = {0003-3472},
  doi       = {10.1016/j.anbehav.2012.05.011},
  pages     = {305 -- 308},
  year      = {2012},
  abstract  = {Honeybees, Apis mellifera, can differ considerably in their birth weights but the consequences of these weight differences for behaviour are unknown. I investigated how these birth weight differences affected their cognitive skills when the bees reached foraging age. Individual sucrose responsiveness measured by the proboscis extension response is a strong determinant of appetitive olfactory learning performance in honeybees. Most of the observed learning differences between individuals or between genetic bee strains correlate with differences in their sucrose responsiveness. My second aim was therefore to investigate whether the sucrose responsiveness of newly emerged bees could predict the learning behaviour of the bees 3 weeks later. Both birth weight and sucrose responsiveness measured at emergence could predict olfactory learning scores as demonstrated by significant positive correlations. Heavy bees and bees with high sucrose responsiveness later learned better than lighter individuals or bees with lower responsiveness to sucrose at emergence. These results demonstrate for the first time a fundamental relationship between sensory responsiveness and morphology at emergence and later cognitive skills in insects. Because sensory responsiveness is closely linked to division of labour in honeybees, differences in weight and sucrose responsiveness at emergence might be involved in regulating division of labour.},
  language  = {en}
}
@article{ScheinerReimSoviketal.2017,
  author    = {Scheiner, Ricarda and Reim, Tina and Sovik, Eirik and Entler, Brian V. and Barron, Andrew B. and Thamm, Markus},
  title     = {Learning, gustatory responsiveness and tyramine differences across nurse and forager honeybees},
  series = {The journal of experimental biology},
  volume    = {220},
  journal   = {The journal of experimental biology},
  publisher = {Company of Biologists Limited},
  address   = {Cambridge},
  issn      = {0022-0949},
  doi       = {10.1242/jeb.152496},
  pages     = {1443 -- 1450},
  year      = {2017},
  abstract  = {Honeybees are well known for their complex division of labor. Each bee sequentially performs a series of social tasks during its life. The changes in social task performance are linked to gross differences in behavior and physiology. We tested whether honeybees performing different social tasks (nursing versus foraging) would differ in their gustatory responsiveness and associative learning behavior in addition to their daily tasks in the colony. Further, we investigated the role of the biogenic amine tyramine and its receptors in the behavior of nurse bees and foragers. Tyramine is an important insect neurotransmitter, which has long been neglected in behavioral studies as it was believed to only act as the metabolic precursor of the better-known amine octopamine. With the increasing number of characterized tyramine receptors in diverse insects, we need to understand the functions of tyramine on its own account. Our findings suggest an important role for tyramine and its two receptors in regulating honeybee gustatory responsiveness, social organization and learning behavior. Foragers, which were more responsive to gustatory stimuli than nurse bees and performed better in appetitive learning, also differed from nurse bees in their tyramine brain titers and in the mRNA expression of a tyramine receptor in the brain. Pharmacological activation of tyramine receptors increased gustatory responsiveness of nurse bees and foragers and improved appetitive learning in nurse bees. These data suggest that a large part of the behavioral differences between honeybees may be directly linked to tyramine signaling in the brain.},
  language  = {en}
}