TY - JOUR A1 - Scheiner, Ricarda A1 - Reim, Tina A1 - Sovik, Eirik A1 - Entler, Brian V. A1 - Barron, Andrew B. A1 - Thamm, Markus T1 - Learning, gustatory responsiveness and tyramine differences across nurse and forager honeybees JF - The journal of experimental biology N2 - 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. KW - Biogenic amines KW - Nurse bee KW - Apis mellifera KW - PER KW - Proboscis extension response Y1 - 2017 U6 - https://doi.org/10.1242/jeb.152496 SN - 0022-0949 SN - 1477-9145 VL - 220 SP - 1443 EP - 1450 PB - Company of Biologists Limited CY - Cambridge ER - TY - JOUR A1 - Reim, Tina A1 - Thamm, Markus A1 - Rolke, Daniel A1 - Blenau, Wolfgang A1 - Scheiner, Ricarda T1 - Suitability of three common reference genes for quantitative real-time PCR in honey bees JF - Apidologie : a quality journal in bee science N2 - 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. KW - gene expression KW - quantitative PCR KW - reference gene KW - stability program KW - Apis mellifera Y1 - 2013 U6 - https://doi.org/10.1007/s13592-012-0184-3 SN - 0044-8435 VL - 44 IS - 3 SP - 342 EP - 350 PB - Springer CY - Paris ER -