@article{ThammRolkeJordanetal.2013,
  author    = {Thamm, Markus and Rolke, Daniel and Jordan, Nadine and Balfanz, Sabine and Schiffer, Christian and Baumann, Arnd and Blenau, Wolfgang},
  title     = {Function and distribution of 5-HT2 receptors in the honeybee (apis mellifera)},
  series = {PLoS one},
  volume    = {8},
  journal   = {PLoS one},
  number    = {12},
  publisher = {PLoS},
  address   = {San Fransisco},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0082407},
  pages     = {12},
  year      = {2013},
  abstract  = {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.},
  language  = {en}
}
@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{FrenchSimcockRolkeetal.2014,
  author    = {French, Alice S. and Simcock, Kerry L. and Rolke, Daniel and Gartside, Sarah E. and Blenau, Wolfgang and Wright, Geraldine A.},
  title     = {The role of serotonin in feeding and gut contractions in the honeybee},
  series = {Journal of insect physiology},
  volume    = {61},
  journal   = {Journal of insect physiology},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0022-1910},
  doi       = {10.1016/j.jinsphys.2013.12.005},
  pages     = {8 -- 15},
  year      = {2014},
  language  = {en}
}
@article{RichterRolkeBlenauetal.2016,
  author    = {Richter, Katharina Natalia and Rolke, Daniel and Blenau, Wolfgang and Baumann, Otto},
  title     = {Secretory cells in honeybee hypopharyngeal gland: polarized organization and age-dependent dynamics of plasma membrane},
  series = {Cell \& tissue research},
  volume    = {366},
  journal   = {Cell \& tissue research},
  publisher = {Springer},
  address   = {New York},
  issn      = {0302-766X},
  doi       = {10.1007/s00441-016-2423-9},
  pages     = {163 -- 174},
  year      = {2016},
  abstract  = {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.},
  language  = {en}
}
@article{KloseRolkeBaumann2017,
  author    = {Klose, Sascha Peter and Rolke, Daniel and Baumann, Otto},
  title     = {Morphogenesis of honeybee hypopharyngeal gland during pupal development},
  series = {Frontiers in zoology},
  volume    = {14},
  journal   = {Frontiers in zoology},
  publisher = {BioMed Central},
  address   = {London},
  issn      = {1742-9994},
  doi       = {10.1186/s12983-017-0207-z},
  year      = {2017},
  abstract  = {Background The hypopharyngeal gland of worker bees contributes to the production of the royal jelly fed to queens and larvae. The gland consists of thousands of two-cell units that are composed of a secretory cell and a duct cell and that are arranged in sets of about 12 around a long collecting duct. Results By fluorescent staining, we have examined the morphogenesis of the hypopharyngeal gland during pupal life, from a saccule lined by a pseudostratified epithelium to the elaborate organ of adult worker bees. The hypopharyngeal gland develops as follows. (1) Cell proliferation occurs during the first day of pupal life in the hypopharyngeal gland primordium. (2) Subsequently, the epithelium becomes organized into rosette-like units of three cells. Two of these will become the secretory cell and the duct cell of the adult secretory units; the third cell contributes only temporarily to the development of the secretory units and is eliminated by apoptosis in the second half of pupal life. (3) The three-cell units of flask-shaped cells undergo complex changes in cell morphology. Thus, by mid-pupal stage, the gland is structurally similar to the adult hypopharyngeal gland. (4) Concomitantly, the prospective secretory cell attains its characteristic subcellular organization by the invagination of a small patch of apical membrane domain, its extension to a tube of about 100 μm in length (termed a canaliculus), and the expansion of the tube to a diameter of about 3 μm. (6) Finally, the canaliculus-associated F-actin system becomes reorganized into rings of bundled actin filaments that are positioned at regular distances along the membrane tube. Conclusions The morphogenesis of the secretory units in the hypopharyngeal gland of the worker bee seems to be based on a developmental program that is conserved, with slight modification, among insects for the production of dermal glands. Elaboration of the secretory cell as a unicellular seamless epithelial tube occurs by invagination of the apical membrane, its extension likely by targeted exocytosis and its expansion, and finally the reorganisation of the membrane-associated F-actin system. Our work is fundamental for future studies of environmental effects on hypopharyngeal gland morphology and development.},
  language  = {en}
}
@misc{KloseRolkeBaumann2017,
  author    = {Klose, Sascha Peter and Rolke, Daniel and Baumann, Otto},
  title     = {Morphogenesis of honeybee hypopharyngeal gland during pupal development},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-395712},
  pages     = {14},
  year      = {2017},
  abstract  = {Background The hypopharyngeal gland of worker bees contributes to the production of the royal jelly fed to queens and larvae. The gland consists of thousands of two-cell units that are composed of a secretory cell and a duct cell and that are arranged in sets of about 12 around a long collecting duct. Results By fluorescent staining, we have examined the morphogenesis of the hypopharyngeal gland during pupal life, from a saccule lined by a pseudostratified epithelium to the elaborate organ of adult worker bees. The hypopharyngeal gland develops as follows. (1) Cell proliferation occurs during the first day of pupal life in the hypopharyngeal gland primordium. (2) Subsequently, the epithelium becomes organized into rosette-like units of three cells. Two of these will become the secretory cell and the duct cell of the adult secretory units; the third cell contributes only temporarily to the development of the secretory units and is eliminated by apoptosis in the second half of pupal life. (3) The three-cell units of flask-shaped cells undergo complex changes in cell morphology. Thus, by mid-pupal stage, the gland is structurally similar to the adult hypopharyngeal gland. (4) Concomitantly, the prospective secretory cell attains its characteristic subcellular organization by the invagination of a small patch of apical membrane domain, its extension to a tube of about 100 μm in length (termed a canaliculus), and the expansion of the tube to a diameter of about 3 μm. (6) Finally, the canaliculus-associated F-actin system becomes reorganized into rings of bundled actin filaments that are positioned at regular distances along the membrane tube. Conclusions The morphogenesis of the secretory units in the hypopharyngeal gland of the worker bee seems to be based on a developmental program that is conserved, with slight modification, among insects for the production of dermal glands. Elaboration of the secretory cell as a unicellular seamless epithelial tube occurs by invagination of the apical membrane, its extension likely by targeted exocytosis and its expansion, and finally the reorganisation of the membrane-associated F-actin system. Our work is fundamental for future studies of environmental effects on hypopharyngeal gland morphology and development.},
  language  = {en}
}
@article{KloseRolkeBaumann2017,
  author    = {Klose, Sascha Peter and Rolke, Daniel and Baumann, Otto},
  title     = {Morphogenesis of honeybee hypopharyngeal gland during pupal development},
  series = {Frontiers in zoology},
  volume    = {14},
  journal   = {Frontiers in zoology},
  publisher = {BioMed Central},
  address   = {London},
  issn      = {1742-9994},
  doi       = {10.1186/s12983-017-0207-z},
  pages     = {2866 -- 2875},
  year      = {2017},
  abstract  = {Background: The hypopharyngeal gland of worker bees contributes to the production of the royal jelly fed to queens and larvae. The gland consists of thousands of two-cell units that are composed of a secretory cell and a duct cell and that are arranged in sets of about 12 around a long collecting duct. Results: By fluorescent staining, we have examined the morphogenesis of the hypopharyngeal gland during pupal life, from a saccule lined by a pseudostratified epithelium to the elaborate organ of adult worker bees. The hypopharyngeal gland develops as follows. (1) Cell proliferation occurs during the first day of pupal life in the hypopharyngeal gland primordium. (2) Subsequently, the epithelium becomes organized into rosette-like units of three cells. Two of these will become the secretory cell and the duct cell of the adult secretory units; the third cell contributes only temporarily to the development of the secretory units and is eliminated by apoptosis in the second half of pupal life. (3) The three-cell units of flask-shaped cells undergo complex changes in cell morphology. Thus, by mid-pupal stage, the gland is structurally similar to the adult hypopharyngeal gland. (4) Concomitantly, the prospective secretory cell attains its characteristic subcellular organization by the invagination of a small patch of apical membrane domain, its extension to a tube of about 100 mu m in length (termed a canaliculus), and the expansion of the tube to a diameter of about 3 mu m. (6) Finally, the canaliculus-associated F-actin system becomes reorganized into rings of bundled actin filaments that are positioned at regular distances along the membrane tube. Conclusions: The morphogenesis of the secretory units in the hypopharyngeal gland of the worker bee seems to be based on a developmental program that is conserved, with slight modification, among insects for the production of dermal glands. Elaboration of the secretory cell as a unicellular seamless epithelial tube occurs by invagination of the apical membrane, its extension likely by targeted exocytosis and its expansion, and finally the reorganisation of the membrane-associated F-actin system. Our work is fundamental for future studies of environmental effects on hypopharyngeal gland morphology and development.},
  language  = {en}
}