TY - JOUR A1 - Thamm, Markus A1 - Rolke, Daniel A1 - Jordan, Nadine A1 - Balfanz, Sabine A1 - Schiffer, Christian A1 - Baumann, Arnd A1 - Blenau, Wolfgang T1 - Function and distribution of 5-HT2 receptors in the honeybee (apis mellifera) JF - PLoS one N2 - Background: Serotonin plays a pivotal role in regulating and modulating physiological and behavioral processes in both vertebrates and invertebrates. In the honeybee (Apis mellifera), serotonin has been implicated in division of labor, visual processing, and learning processes. Here, we present the cloning, heterologous expression, and detailed functional and pharmacological characterization of two honeybee 5-HT2 receptors. Methods: Honeybee 5-HT2 receptor cDNAs were amplified from brain cDNA. Recombinant cell lines were established constitutively expressing receptor variants. Pharmacological properties of the receptors were investigated by Ca2+ imaging experiments. Quantitative PCR was applied to explore the expression patterns of receptor mRNAs. Results: The honeybee 5-HT2 receptor class consists of two subtypes, Am5-HT2 alpha and Am5-HT2 beta. Each receptor gene also gives rise to alternatively spliced mRNAs that possibly code for truncated receptors. Only activation of the full-length receptors with serotonin caused an increase in the intracellular Ca2+ concentration. The effect was mimicked by the agonists 5-methoxytryptamine and 8-OH-DPAT at low micromolar concentrations. Receptor activities were blocked by established 5-HT receptor antagonists such as clozapine, methiothepin, or mianserin. High transcript numbers were detected in exocrine glands suggesting that 5-HT2 receptors participate in secretory processes in the honeybee. Conclusions: This study marks the first molecular and pharmacological characterization of two 5-HT2 receptor subtypes in the same insect species. The results presented should facilitate further attempts to unravel central and peripheral effects of serotonin mediated by these receptors. Y1 - 2013 U6 - https://doi.org/10.1371/journal.pone.0082407 SN - 1932-6203 VL - 8 IS - 12 PB - PLoS CY - San Fransisco 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 - TY - JOUR A1 - French, Alice S. A1 - Simcock, Kerry L. A1 - Rolke, Daniel A1 - Gartside, Sarah E. A1 - Blenau, Wolfgang A1 - Wright, Geraldine A. T1 - The role of serotonin in feeding and gut contractions in the honeybee JF - Journal of insect physiology KW - Honeybee KW - Apis mellifera KW - Serotonin KW - 5-HT KW - 5-HT receptor KW - Gut contractions Y1 - 2014 U6 - https://doi.org/10.1016/j.jinsphys.2013.12.005 SN - 0022-1910 SN - 1879-1611 VL - 61 SP - 8 EP - 15 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Richter, Katharina Natalia A1 - Rolke, Daniel A1 - Blenau, Wolfgang A1 - Baumann, Otto T1 - Secretory cells in honeybee hypopharyngeal gland: polarized organization and age-dependent dynamics of plasma membrane JF - Cell & tissue research N2 - The honeybee hypopharyngeal gland consists in numerous units, each comprising a secretory cell and a canal cell. The secretory cell discharges its products into a convoluted tubular membrane system, the canaliculus, which is surrounded at regular intervals by rings of actin filaments. Using probes for various membrane components, we analyze the organization of the secretory cells relative to the apicobasal configuration of epithelial cells. The canaliculus was defined by labeling with an antibody against phosphorylated ezrin/radixin/moesin (pERM), a marker protein for the apical membrane domain of epithelial cells. Anti-phosphotyrosine visualizes the canalicular system, possibly by staining the microvillar tips. The open end of the canaliculus leads to a region in which the secretory cell is attached to the canal cell by adherens and septate junctions. The remaining plasma membrane stains for Na,K-ATPase and spectrin and represents the basolateral domain. We also used fluorophore-tagged phalloidin, anti-phosphotyrosine and anti-pERM as probes for the canaliculus in order to describe fine-structural changes in the organization of the canalicular system during the adult life cycle. These probes in conjunction with fluorescence microscopy allow the fast and detailed three-dimensional analysis of the canalicular membrane system and its structural changes in a developmental mode or in response to environmental factors. KW - Hypopharyngeal gland KW - Cell polarity KW - Moesin KW - Actin cytoskeleton KW - Honeybee Y1 - 2016 U6 - https://doi.org/10.1007/s00441-016-2423-9 SN - 0302-766X SN - 1432-0878 VL - 366 SP - 163 EP - 174 PB - Springer CY - New York ER -