TY - JOUR A1 - Becher, Matthias A. A1 - Grimm, Volker A1 - Thorbek, Pernille A1 - Horn, Juliane A1 - Kennedy, Peter J. A1 - Osborne, Juliet L. T1 - BEEHAVE: a systems model of honeybee colony dynamics and foraging to explore multifactorial causes of colony failure JF - Journal of applied ecology : an official journal of the British Ecological Society N2 - BEEHAVE offers a valuable tool for researchers to design and focus field experiments, for regulators to explore the relative importance of stressors to devise management and policy advice and for beekeepers to understand and predict varroa dynamics and effects of management interventions. We expect that scientists and stakeholders will find a variety of applications for BEEHAVE, stimulating further model development and the possible inclusion of other stressors of potential importance to honeybee colony dynamics. KW - Apis mellifera KW - colony decline KW - cross-level interactions KW - feedbacks KW - foraging KW - modelling KW - multiple stressors KW - multi-agent simulation KW - predictive systems ecology KW - Varroa destructor Y1 - 2014 U6 - https://doi.org/10.1111/1365-2664.12222 SN - 0021-8901 SN - 1365-2664 VL - 51 IS - 2 SP - 470 EP - 482 PB - Wiley-Blackwell CY - Hoboken ER - TY - THES A1 - Reim, Tina T1 - Biogene Aminrezeptoren bei der Honigbiene Apis mellifera T1 - Biogenic amine receptors in the honey bee Apis mellifera BT - Charakterisierung des Tyramin 2-Rezeptors und die Beteiligung der Octopamin- und Tyraminrezeptoren an der Steuerung der altersabhängigen Arbeitsteilung N2 - Die Honigbiene Apis mellifera zeigt innerhalb einer Kolonie eine an das Alter gekoppelte Arbeitsteilung. Junge Honigbienen versorgen die Brut (Ammenbienen), während ältere Honigbienen (Sammlerinnen) außerhalb des Stocks Pollen und Nektar eintragen. Die biogenen Amine Octopamin und Tyramin sind an der Steuerung der Arbeitsteilung maßgeblich beteiligt. Sie interagieren mit Zielzellen über die Bindung an G Protein gekoppelte Rezeptoren. A. mellifera besitzt fünf charakterisierte Octopaminrezeptoren (AmOctαR1, AmOctβR1-4), einen charakterisierten Tyraminrezeptor (AmTyr1) sowie einen weiteren putativen Tyraminrezeptor. In der vorliegenden Arbeit wurde dieser putative Aminrezeptor als zweiter Tyraminrezeptor (AmTyr2) identifiziert, lokalisiert und pharmakologisch charakterisiert. Die von der cDNA abgeleitete Aminosäuresequenz weist strukturelle Eigenschaften und konservierte Motive von G Protein gekoppelten Rezeptoren auf. Phylogenetisch ordnet sich der AmTyr2 Rezeptor bei den Tyramin 2 Rezeptoren anderer Insekten ein. Die funktionelle und pharmakologische Charakterisierung des putativen Tyraminrezeptors erfolgte in modifizierten HEK293 Zellen, die mit der Rezeptor cDNA transfiziert wurden. Die Applikation von Tyramin aktiviert Adenylylcyclasen in diesen Zellen und resultiert in einem Anstieg des intrazellulären cAMP Gehalts. Der AmTyr2 Rezeptor kann durch Tyramin in nanomolaren Konzentrationen halbmaximal aktiviert werden. Während es sich bei Octopamin um einen wirkungsvollen Agonisten des Rezeptors handelt, sind Mianserin und Yohimbin effektive Antagonisten. Für die Lokalisierung des Rezeptorproteins wurde ein polyklonaler Antikörper generiert. Eine AmTyr2-ähnliche Immunreaktivität zeigt sich im Gehirn in den optischen Loben, den Antennalloben, dem Zentralkomplex und in den Kenyon Zellen der Pilzkörper. Des Weiteren wurde die Rolle der Octopamin- und Tyraminrezeptoren bei der Steuerung der altersabhängigen Arbeitsteilung analysiert. Die Genexpression des AmOctαR1 in verschiedenen Gehirnteilen korreliert unabhängig vom Alter mit der sozialen Rolle, während sich die Genexpression von AmOctβR3/4 und den Tyraminrezeptoren AmTyr1 und AmTyr2 maximal mit dem Alter aber nicht der sozialen Rolle ändert. Sammlerinnen weisen einen höheren Octopamingehalt im Gesamtgehirn auf als Ammenbienen; bei Tyramin zeigen sich keine Unterschiede. Während Tyramin offensichtlich keine direkte Rolle spielt, werden durch Octopamin gesteuerte Prozesse der altersabhängigen Arbeitsteilung bei der Honigbiene vermutlich über den AmOctαR1 vermittelt. Die Ergebnisse der vorliegenden Arbeit zeigen die wichtige Rolle von biogenen Aminen, insbesondere Octopamin bei der sozialen Organisation von Insektenstaaten. N2 - The honey bee Apis mellifera exhibits an age-dependent division of labour. Young bees take care of the brood (nurse bees), while older honey bees (foragers) leave the hive to provide the colony with pollen and nectar. The biogenic amines octopamine and tyramine are significantly involved in regulating the division of labour. They interact with target cells via binding to G protein-coupled receptors. A. mellifera has five characterised octopamine receptors (AmOctαR1, AmOctβR1-4), one characterised tyramine receptor (AmTyr1) and an additional putative tyramine receptor. In the present study, the putative amine receptor was identified as a second tyramine receptor (AmTyr2), was localized and characterised pharmacologically. The deduced amino acid sequence shows structural properties and conserved motifs of G protein-coupled receptors. Phylogenetically the AmTyr2 receptor clusters with tyramine 2 receptors from other insect species. Functional and pharmacological characterisation of the putative tyramine receptor was carried out using modified HEK293 cells trans¬fected with the receptor cDNA. Application of tyramine activates adenylyl cyclases in these cells, which leads to an elevated intracellular cAMP level. Half maximal activation can be achieved by applying tyramine with concentrations in the nanomolar range. While octopa¬mine is an effective agonist of the receptor, mianserin and yohimbine are the most effective antagonists. A polyclonal antibody was generated for the localisation of the receptor protein. AmTyr2 like immunoreactivity can be observed in the optic lobes, the Kenyon cells of the mushroom bodies, the antennal lobes and the central complex of the brain. Furthermore, the role of the octopamine and tyramine receptors in regulating the age-dependent division of labour was analysed. The gene expression of the AmOctαR1 in different brain neuropiles correlates with the social role of the honey bee, while the gene expression of AmOctβR3/4, AmTyr1 and AmTyr2 mostly changes with age but not social role. Additionally, foragers have higher octopamine brain titres than nurse bees. No differences can be observed for the titre of tyramine. Octopamine-regulated processes in age-dependent division of labour are probably mediated via the AmOctαR1. Tyramine has obviously no direct impact on the age-dependent division of labour. The present study shows the important role of biogenic amines, particularly octopamine in the social organisation of insect societies. KW - Apis mellifera KW - honey bee KW - Honigbiene KW - biogene Amine KW - biogenic amines KW - Octopamin KW - octopamine KW - Tyramin KW - tyramine KW - Arbeitsteilung KW - division of labor Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-80982 ER - TY - JOUR A1 - Scheiner, Ricarda T1 - Birth weight and sucrose responsiveness predict cognitive skills of honeybee foragers JF - Animal behaviour N2 - 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. KW - Apis mellifera KW - birth weight KW - division of labour KW - foraging KW - honeybee KW - learning KW - maternal provisioning KW - sucrose responsiveness Y1 - 2012 U6 - https://doi.org/10.1016/j.anbehav.2012.05.011 SN - 0003-3472 VL - 84 IS - 2 SP - 305 EP - 308 PB - Elsevier CY - London ER - TY - JOUR A1 - Blenau, Wolfgang A1 - Thamm, Markus T1 - Distribution of serotonin (5-HT) and its receptors in the insect brain with focus on the mushroom bodies lessons from Drosophila melanogaster and Apis mellifera JF - Arthropod structure & development N2 - The biogenic amine serotonin (5-hydroxytryptamine, 5-HT) plays a key role in regulating and modulating various physiological and behavioral processes in both protostomes and deuterostomes. The specific functions of serotonin are mediated by its binding to and subsequent activation of membrane receptors. The vast majority of these receptors belong to the superfamily of G-protein-coupled receptors. We report here the in vivo expression pattern of a recently characterized 5-HT(1) receptor of the honeybee Apis mellifera (Am5-HT(1A)) in the mushroom bodies. In addition, we summarize current knowledge on the distribution of serotonin and serotonin receptor subtypes in the brain and specifically in the mushroom bodies of the fruit fly Drosophila melanogaster and the honeybee. Functional studies in these two species have shown that serotonergic signaling participates in various behaviors including aggression, sleep, circadian rhythms, responses to visual stimuli, and associative learning. The molecular, pharmacological, and functional properties of identified 5-HT receptor subtypes from A. mellifera and D. melanogaster will also be summarized in this review. KW - Apis mellifera KW - G-protein-coupled receptor KW - Drosophila melanogaster KW - Mushroom body KW - Serotonin Y1 - 2011 U6 - https://doi.org/10.1016/j.asd.2011.01.004 SN - 1467-8039 VL - 40 IS - 5 SP - 381 EP - 394 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Reim, Tina A1 - Scheiner, Ricarda T1 - Division of labour in honey bees: age- and task-related changes in the expression of octopamine receptor genes JF - Insect molecular biology N2 - 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. KW - Apis mellifera KW - behavioural plasticity KW - G-protein coupled receptor KW - AmOctR1 KW - AmOctR3 KW - 4 Y1 - 2014 U6 - https://doi.org/10.1111/imb.12130 SN - 0962-1075 SN - 1365-2583 VL - 23 IS - 6 SP - 833 EP - 841 PB - Wiley-Blackwell CY - Hoboken ER - 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 - Gisder, Sebastian A1 - Schüler, Vivian A1 - Horchler, Lennart L. A1 - Groth, Detlef A1 - Genersch, Elke T1 - Long-Term Temporal Trends of Nosema spp. Infection Prevalence in Northeast Germany BT - Continuous Spread of Nosema ceranae, an Emerging Pathogen of Honey Bees (Apis mellifera), but No General Replacement of Nosema apis JF - Frontiers in cellular and infection microbiology N2 - The Western honey bee (Apis mellifera) is widely used as commercial pollinator in worldwide agriculture and, therefore, plays an important role in global food security. Among the parasites and pathogens threatening health and survival of honey bees are two species of microsporidia, Nosema apis and Nosema ceranae. Nosema ceranae is considered an emerging pathogen of the Western honey bee. Reports on the spread of N. ceranae suggested that this presumably highly virulent species is replacing its more benign congener N. apis in the global A. mellifera population. We here present a 12 year longitudinal cohort study on the prevalence of N. apis and N. ceranae in Northeast Germany. Between 2005 and 2016, a cohort of about 230 honey bee colonies originating from 23 apiaries was sampled twice a year (spring and autumn) resulting in a total of 5,600 bee samples which were subjected to microscopic and molecular analysis for determining the presence of infections with N. apis or/and N. ceranae. Throughout the entire study period, both N. apis- and N. ceranae-infections could be diagnosed within the cohort. Logistic regression analysis of the prevalence data demonstrated a significant increase of N. ceranae-infections over the last 12 years, both in autumn (reflecting the development during the summer) and in spring (reflecting the development over winter) samples. Cell culture experiments confirmed that N. ceranae has a higher proliferative potential than N. apis at 27. and 33 degrees C potentially explaining the increase in N. ceranae prevalence during summer. In autumn, characterized by generally low infection prevalence, this increase was accompanied by a significant decrease in N. apis- infection prevalence. In contrast, in spring, the season with a higher prevalence of infection, no significant decrease of N. apis infections despite a significant increase in N. ceranae infections could be observed. Therefore, our data do not support a general advantage of N. ceranae over N. apis and an overall replacement of N. apis by N. ceranae in the studied honey bee population. KW - honey bee KW - Apis mellifera KW - Nosema spp. KW - epidemiology KW - replacement Y1 - 2017 U6 - https://doi.org/10.3389/fcimb.2017.00301 SN - 2235-2988 VL - 7 PB - Frontiers Research Foundation CY - Lausanne 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 - Becher, Matthias A. A1 - Osborne, Juliet L. A1 - Thorbek, Pernille A1 - Kennedy, Peter J. A1 - Grimm, Volker T1 - Towards a systems approach for understanding honeybee decline - a stocktaking and synthesis of existing models JF - Journal of applied ecology : an official journal of the British Ecological Society N2 - 1. The health of managed and wild honeybee colonies appears to have declined substantially in Europe and the United States over the last decade. Sustainability of honeybee colonies is important not only for honey production, but also for pollination of crops and wild plants alongside other insect pollinators. A combination of causal factors, including parasites, pathogens, land use changes and pesticide usage, are cited as responsible for the increased colony mortality. 2. However, despite detailed knowledge of the behaviour of honeybees and their colonies, there are no suitable tools to explore the resilience mechanisms of this complex system under stress. Empirically testing all combinations of stressors in a systematic fashion is not feasible. We therefore suggest a cross-level systems approach, based on mechanistic modelling, to investigate the impacts of (and interactions between) colony and land management. 3. We review existing honeybee models that are relevant to examining the effects of different stressors on colony growth and survival. Most of these models describe honeybee colony dynamics, foraging behaviour or honeybee - varroa mite - virus interactions. 4. We found that many, but not all, processes within honeybee colonies, epidemiology and foraging are well understood and described in the models, but there is no model that couples in-hive dynamics and pathology with foraging dynamics in realistic landscapes. 5. Synthesis and applications. We describe how a new integrated model could be built to simulate multifactorial impacts on the honeybee colony system, using building blocks from the reviewed models. The development of such a tool would not only highlight empirical research priorities but also provide an important forecasting tool for policy makers and beekeepers, and we list examples of relevant applications to bee disease and landscape management decisions. KW - Apis mellifera KW - colony decline KW - feedbacks KW - integrated model KW - multiple stressors KW - predictive systems ecology KW - review Y1 - 2013 U6 - https://doi.org/10.1111/1365-2664.12112 SN - 0021-8901 VL - 50 IS - 4 SP - 868 EP - 880 PB - Wiley-Blackwell CY - Hoboken ER -