747 research outputs found
) in agricultural landscapes
No full textAlthough habitat fragmentation and agricultural intensification are known as threads to pollinator diversity, little is known about consequences for population size and genetic diversity. Here, we combined detailed field observations, molecular approaches and GIS-based quantification of landscape structure (measured by proportions of seminatural habitats and proportions of mass flowering crops) to get new insights into driving forces of population dynamics of the bumblebee species Bombus pascuorum. Comparing 13 agriculturally dominated landscape sectors, we found the proportion of mass flowering crops to positively influence bumblebee abundance whereas the proportion of seminatural habitats was of minor importance. We used microsatellites to quantify landscape-related colony densities, inbreeding and population substructure. Detected colony densities did not correlate with landscape parameters or with local worker abundance, measured by field observations. These results indicate that increased worker abundances within landscapes are rather due to greater colony sizes than due to an increased number of nests. We found significant population substructure, measured by F-ST and seven landscape sectors to bear significantly increased inbreeding values (F-IS). F-IS was strongly varying between sectors but did not correlate with landscape structure. Moreover, F-IS had a significantly negative effect on colony size, demonstrating the importance of genetic diversity on population fitness at a landscape scale. We suggest that inbreeding levels might be related to the temporal variation of food resources and population sizes in agricultural landscapes
The genetic control of the social parasitism in the Cape honey bee, A. m. capensis ESCH
No full textDiese Arbeit befasst sich mit der genetischen Kontrolle des sozialen Parasitismus der Kapbiene, A. m. capensis. Im ersten Teil dieser Arbeit ergab eine Mikrosatelliten-basierte Analyse Hinweise, dass Thelytokie in der Kapbiene von einem genetischen Locus kontrolliert wird. Im zweiten Teil dieser Arbeit werden Next-Generation-Sequencing Daten der mapping population generiert. Die anschließenden SNP-Analysen führten zur Identifizierung des Thelytokie-kontrollierenden Locus. Zudem wird ein balanciert nachteiliges Allelsystem abgeleitet, das erklärt weshalb Thelytokie nur bei Kapbienen vorkommt. Im dritten Teil dieser Arbeit wird die Entwicklung von A. m. capensis sozialen Parasiten mit sozialen Arbeiterinnen, unter Verwendung von RNAseq-Daten aufeinanderfolgender Zeitpunkte, verglichen. Gene, die in die Entwicklung von sozialen Parasiten involviert sind, wurden identifizieren.This thesis examines the genetic control of the social parasitism of the Cape bee, A. m. capensis. In the first part of this thesis, a microsatellite-based analysis of a wild A. m. capensis mapping population provided support that thelytoky in the Cape bee is controlled by a single genetic locus. In the second part of this thesis, next generation sequencing data of the mapping population are generated. The subsequent SNP analyses led to the identification of the thelytoky controlling locus. Additionally, a balanced detrimental allele system was inferred, which explains why thelytoky only occurs in A. m. capensis. In the third part of this thesis, the development of A. m. capensis social parasites and social workers are compared using RNAseq data of subsequent time points. Genes that are involved in the development of A. m. capensis social parasites are identified.vorgelegt von Denise Aume
THE QUALITY OF HONEY FOR BEES AND MAN
No full textHoney is used both as food ingredient and in a variety of treatments for diverse ailments. For this reason, consumer expectation of its quality and purity is particularly high. The aim of the BEE SHOP Honey Department was the evaluation of honey quality and authenticity, through the development of new instrument for the verification of the botanical origin and the presence of impurities. Honey quality can be important also for the colony itself and therefore the Honey Department focused on the physiological properties of honey which can be beneficial for honeybees and for the prevention of bee diseases. Testing the origin of honeybees is also important to enforce the EC directive for organic beekeeping, since the use of regional bee strains is an important quality criterion for organic honey. To identify the origin of the honeybee the BEE SHOP Honey Department has developed a DNA based diagnostic tool. Through the analysis of honey and nectar samples by HPLC-MS-MS methods, suitable markers were detected for Robinia, Tilia, Citrus, Eucalyptus and chestnut unifloral honeys, and the following phytochemicals have been proposed for the determination of honey floral origins: myricetin, tricetin and luteolin for Eucalyptushoney, kynurenic acid related compounds for chestnut honey, terpenoids for Linden honey, hesperetin for Citrus honey, kaempferol rhamnosides for Acacia (Robinia) honey. Two novel protocols were introduced for the evaluation of honey quality: DRIFTS (Diffuse Reflectance Infrared Fourier Transform Spectroscopy) and HR-NMR (High Resolution Nuclear Magnetic Resonance). These techniques, coupled with appropriate multivariate statistical analysis, demonstrated to be suitable for the verification of botanical origin and the detection of honey adulteration by sugar syrups. The HR-NMR method seems to be suitable also for a quantitative determination of the adulteration levels. A new sensitive enzyme-linked immunoassay (ELISA) for the quantitative determination of apalbumin1a major compound of the royal jelly (RJ) proteins in honey has been developed. This protein can be used as a marker for honey quality because its concentration varies with the botanical origin. The highest content was determined in chestnut honey, in comparison with acacia and rape honey, while the lowest amount was detected in honey obtained supplying bee colony with saccharose syrup. The antimicrobial potential of honey based on proteins of honeybee origin was tested by microtiter based assays. The inhibition of P. larvae growth was observed in the protein fraction of cherry and rape honeys and honeydew. Moreover, a protein fraction corresponding to apalbumin2a has been identified in honey. This protein, purified from RJ, had specific antibiotic properties against P. larvae. The anti quorum-sensing (QS) activities of honeys with different floral origin have been evaluated, using bacterial strains in which quorum-sensing activated the pigment violacein. 29 honey samples inhibited QS even at the lowest concentration. The anti-QS activity was concentration-dependent and relied on the floral origin. Among all honeys, chestnut and linden samples were the strongest quorum-sensing inhibitors (QSI)
Pheromone-mediated reproductive dominance hierarchies among pseudo-clonal honeybee workers (Apis mellifera capensis)
No full textHoney bee colonies are characterised by well-developed reproductive division of labour between the queen and workers. Here, we test whether this reproductive division of labour is evident in both the socially parasitic workers that invade a colony as well as in their offspring generation. We infected six Apis mellifera scutellata host colonies with pseudo-clonal socially parasitic Cape honeybee workers (Apis mellifera capensis). We show that the first generation of socially parasitic workers can monopolize reproduction within host colonies. Of the initially invading parasites, 94.4% became reproductive pseudoqueens with activated ovaries and produced queen-like pheromones. Their offspring, however, had much lower levels of ovary activation (3.1%), yet 89% showed fatty acid synthesis typical of the queen substance (9-oxo-2(E)-decenoic acid) biochemical pathway. However, in these second-generation workers, the last oxidation step from the precursor (9-hydroxy-2(E)-decenoic acid) to the queen substance was interrupted and appears to be required for reproductive dominance in honeybee workers. Our data show that despite the absence of genetic diversity, residual queen mandibular pheromone (QMP) variation is sufficient to establish reproductive dominance hierarchies among parasitic workers. Consequently, QMP produced by a group of workers can maintain reproductive division of labour in queenless honeybee colonies
The wild honeybees of Sudan - a test case for conservation, apiculture and invasive species
No full textWegen des vielfachen Imports von europäischen Honigbienen Apis mellifera und der zufälligen Einführung der Zwerghonigbiene Apis florea in den Sudan, untersuchte ich die möglichen Auswirkungen dieser beiden Arten auf die einheimischen Honigbienen des Sudans. Maternale Introgression in lokale Genpools wurde durch Genotypisierung der mitochondrialen (mt) DNA von wilden Bienenvölkern aus dem ganzen Land erfasst. Die nativen Bienen im Sudan tragen sechs verschiedene mt-Haplotypen (A1 , A4, A8 , A13, O1, O1’). Nur in den Regionen, in denen Imkerei betrieben wird, finden sich auch Bienenvölker mit dem europäischen Haplotyp C2. Obwohl es keine Hinweise auf maternale Introgression durch Schwärmen von Bienenvölkern gibt, findet in Regionen mit kommerzieller Imkerei Introgression in lokale Genpools durch die Paarung von Königinnen mit Drohnen europäischer Herkunft statt. Beide eingeführte Arten haben bisher nicht zu einem Verdrängungswettbewerb mit den nativen Bienen aus dem Sudan geführt. Allerdings hat Apis florea höhere Volksdichten als die einheimischen wilden Kolonien von A. mellifera. Dies deutet darauf hin, dass die Zwerghonigbiene im Sudan ein hohes invasives Potential besitzt.von Mogbel Ahmed Abdalla El-Niweir
INBREEDING EFFECTS IN FLIGHT MUSCLE MITOCHONDRIA OF Apis mellifera L.
No full textln f-light muscle mitochondria of drones and rvorkcrs lApis mellifera L.) cnzymc activities shorved srgnrficant changes after inbrecding. fhe genonre sccms to llrve only moderatc etlect on this mitochondrial inbreeding depression. It is shou.n that mainll'cytoplasmic factors are aft-ecting thc changcs in enzymc activitl'observed after inbrecding
Reproductive biology of the Cape honeybee : a critique of Beekman et al.
No full textA critique of “Asexually Produced Cape Honeybee Queens (Apis mellifera capensis) Reproduce Sexually”: Laying workers of the Cape honeybee parthenogenetically produce female offspring whereas queens typically produce males. Beekman et al. confirm this observation, which has repeatedly been reported over the last 100 years including the notion that natural selection should favor asexual reproduction in A. m. capensis. They attempt to support their arguments with an exceptionally surprising finding that A. m. capensis queens can parthenogenetically produce diploid homozygous queen offspring (homozygous diploid individuals develop into diploid males in the honeybee). Beekman et al. suggest that these homozygous queens are not viable because they did not find any homozygous individuals beyond the third larval instar. Even if this were true, such a lethal trait should be quickly eliminated by natural selection. The identification of sex (both with molecular and morphological markers) is possible but notoriously difficult in honeybees at the early larval stages. Ploidy is however a reliable indicator and we therefore suggest that these “homozygous” larvae found in queen cells are actually drones reared from unfertilized eggs, a phenomenon well known by honeybee queen breeders.http://www.ncbi.nlm.nih.gov/pubmed/22581844ab201
College of Law Ohio State University Class of 1990
No full textFaculty (pictured): Ash, Barbara; Beytagh, Francis X., Dean; Braunstein, Michael; Caust-Ellenbogen, Sanford; Chow, Daniel C. K.; Clovis, Albert L.; Fink, Howard P.; Goldberger, David; Greenbaum, Arthur F.; Halpern, Sheldon W.; Hebert, L. Camille; Henderson, Jack, Associate Dean; Herman, Lawrence; Holoch, Alan; Jacobs, Louis A.; Jost, Timothy; Kindred, Michael; Kozyris, P. John; Krauskopf, Joan; Laughlin, Stanley K.; Lynn, Robert J.; Meeks, James E.; Modjeska, Lee; Murphy, Earl Finbar; Murphy, Joanne Wharton, Assistant Dean; Pernell, LeRoy; Quigley, John B.; Rivera, Rhonda R.; Rogers, Nancy H.; Rose, Michael D.; Samansky, Allan J.; Snyder, Barbara R.; Travalio, Gregory, Associate Dean; Verdun, Vincene; Whaley, Douglas; Williams, David, II; Wilson, Charles; Class Officers: Campbell, Drew H., Editor-in-Chief Ohio State Law Journal; Cordial, Catherine D., SBA Vice-President; Dukes, Patrick M., SBA President; Hopper, John W., Editor-in-Chief Journal on Dispute Resolution; Sarver, James K., Chief Justice Honor Council; Smith, Monte G., Chief Justice Moot Court; Class Members (pictured): Allen, Mitchell W.; Antalovich, Susan K.; Arthur, Geoffrey W.; Astrov, Harry Todd; Ayish, Sam Nadeen; Bajus, Susan M.; Barbaree, Tracey A.; Baringer, Linette Stratford; Baringer, Randal S.; Barker, David P.; Barnet, Michael N.; Becka Maryanne; Bence, David S.; Berns, Jordan; Bilott, Robert A.; Black, Lori A.; Blaha, Margaret M.; Bolender, Julie M.; Boniface, Diane C.; Booker, Marc A.; Bostic, Joy; Bowers, Brenda; Bravo, Eric S.; Breitenbach, Thomas A.; Bressman, David A.; Britton, Brad; Brown, Barbara S.; Brown, Chevella R.; Burrington, Lori A.; Burton, Kelly M.; Calvin, Neil P.; Carr, Greg E.; Casias, Edward J.; Clark, D. Lewis, Jr.; Cliffel, Albert P., III; Collins, Stephen; Core, Anthony E.; Creamer, Robert J.; Culotta, Vincent A.; Cunningham, Ruth A.; Danford, Barbara N.; Dawe, Timothy J.; Day, Marilyn Kuhl; Demske, Gregory E.; Devito, Christopher M.; Dewitt, Timothy R.; Dugic, Melody A.; English, Katrina Miller; Feldkamp, Janet K.; Finley, Price D.; Flowers, Paul W.; Fried, Gil B.; Gamlin, John P.; Gantz, William M.; Geyer, Thomas E.; Goldberg, Scott; Goodson, Antionice D.; Groeber, John A.; Guy, Rosalyn L.; Hagen, Melissa L.; Hahn, Richard L.; Infante, Renee A.; Kozar, Barbara L.; Hanes, Kimberley K.; Harter, Elizabeth Deer; Harter, Sean; Harvey, R. Scott; Hathaway, Lynn E.; Heid, Brigid E.; Heil, Patricia; Henke, Robert E.; Hilburn, Regina; Hix, Kimberly; Hoffman, William D.; Houck, Annette M.; Human, Randy; Izenson, Daniel E.; Jacques, Laurie N.; Janik, Frank J., III; Joondeph, Jerome J., Jr.; Jordan, Jeffery H.; Kastelic, John A.; Kendall, John S.; Kennedy, Julia S.; Kennedy, Robert S.; Keys, Marjorie L.; Klein, Daniel A.; Klotz, Karla L.; Kramer, John F.; Kuns, Constance M.; Lampkin, Robin E.; Larson, Peter N.; Lee, Deborah A.; Leedy, Lynda M.; Lenzotti, Dean M.; Lepley, Charles R.; List, D. Andrew; Limage, Bret L.; Loch, Amy L.; Maier, Robert C.; Marshall, Michelle; Matheson, Carolyn; McCarroll, Judith E.; McCarthy, Patrick F.; McClaren, Robert J.; McKee, Kenneth A.; Mekaru, Daniel Y.; Mendel, Todd R.; Merrin, Richard C.; Mikes, Randall W.; Morse, Kerry L.; Munshower, Frank; Musgrave, Megan L.; Nakasian, William E.; Naraine, Susan V.; Neiger, Jan Alan; Nick, Paul M.; Oldach, William H., III; O Neal, Tracy D.; Padilla, James J.; Palmer, Todd F.; Peltier, Suzanne; Peltz, Carol H.; Perez, Luis A.; Pfarrer, David A.; Philbrick, Valerie; Polgar, Matthew J.; Pousoulides, Dimitrios; Reiter, Mary L.; Rhodehamel, David R.; Rice, Michael W.; Richert, John R.; Richter, Michael P.; Riedesel, Lisa; Riehemann, Walter E.; Roberts, Debra L.; Robertson, Jean R.; Rodriguez, Laura M.; Rose, Daniel C.; Rossie, Linda M.; Rothchild, Barry A.; Rouhana, Anna Marie; Sabine, Glenn; Sanders, Daniel H.; Saunders, Kenneth L.; Schroeder, Michael A.; Seidensticker, John W.; Sewards, Frederick A.; Sheppard, John B.; Shillington, Beth C.; Shoemaker, Larry B.; Shoman, Elizabeth L.; Sollenberger, Teresa L.; Sotak, Mark W.; Squire, Julie; Stadnicar, Joseph W.; Stahl, Audrey; Steiner, Jane E.; Stewart, Melissa; Stull, Melissa; Sutton, Jeffrey S.; Talbott, D. Casey; Triplett, Angela R.; Vandervoort, Terre; Vawter, Jana R.; Veen, Daniel; Vourlis, Simina; Wantuck, Michael S.; Watkins, Valetha A.; Watters, Elizabeth J.; Webb, Kenneth E., Jr.; Webb, Tracy L. Riddle; White, Daniel S.; Williams, Brad; Wright, Bradley A.; Yates, James B.; Zalimeni, Gail M.; Zox, Meliss
Of mites and men
No full textDie brut-parasitierende Milbe Varroa destructor zerstört Völker der Honigbiene Apis mellifera. Völker, die nicht mittels Akariziden behandelt wurden, sterben typischerweise inhalb von 3 Jahren nach Varroa-Befall. Diese Behandlung entfernt jedoch den selektiven Druck, welcher für die Evolution Varroa-resistenter Merkmale nötig wäre. Wenn Bienenpopulation unbehandlet bleiben, wäre zwar die intiale Völkerverlustrate ziemlich hoch, jedoch könnte in diesem Fall Selektion die Evolution von Resistenzmerkmalen vorantreiben. Innerhalb solcher resistenten Populationen ist die Inhibierung der Reproduktion der Varroa ein gemeinsames Merkmal. Meine Doktorarbeit hatte das Ziel die genomische Basis für die Evolution der Varroa-Resistenz in zwei verschiedenen Honigbienenpopulationen zu untersuchen: einer Population auf Gotland (Schweden) und einer anderen in der Nähe von Toulouse (Frankreich). Ich konnte Gene und physiologische Signalwege identifizieren, welche mit der Resistenz in diesen Populationen in Verbindung stehen. Des Weiteren betrachtete ich, was uns die gefundenen Gene und Signalwege über die Reproduktion der Varroa verraten und welche Folgen diese Ergebnisse für die Zucht Varroa-resistenter Honigbienen haben könnten.The brood-parasitic mite has devastated colonies of the honey bee Apis mellifera. Colonies of A. mellifera, untreated with acaricides, typically die within three years of Varroa infestation. However, this removes the selective pressure for the evolution of Varroa-resistance traits in the bees. Although initial colony losses can be high, when populations are left untreated with acaricides, selection can drive the evolution of resistance traits. Within these resistant populations, the inhibition of Varroa reproductions is a common trait. My PhD aimed to investigate the genomic basis for the evolution of Varroa resistance in two populations of A. mellifera: one from Gotland, Sweden, and the other from near Toulouse, France. I identify genes and physiological pathways linked to resistance in these populations and consider what they can tell us about the reproduction of Varroa as well as the implications of these results for the breeding of Varroa-resistant honey bees.vorgelegt von Benjamin Hanson Conlo
Are there really cryptic species within the myrmecophilous butterfly species Phengaris (Maculinea) teleius and P. (M.) nausithous (Lepidoptera: Lycaenidae)? : analyses across Eurasian distribution ranges, confusing effects of the endosymbiotic bacterial parasite Wolbachia, and implications for Phengaris (Maculinea) conservation
No full textGegenstand der hier vorgestellten Arbeit ist eine phylogenetische und phylogeographische Untersuchung zur Existenz von kryptischen Arten bei den Schmetterlingsarten Phengaris teleius und Phengaris nausithous. Bei beiden Arten konnte eine tiefe mitochondriale phylogenetische Aufspaltung aufgezeigt werden, welche vor ca. 0.65–1.97 Millionen Jahren begann. Die Aufspaltung fand keine Entsprechung bei dem analysierten Mikrosatelliten-Datensatz, jedoch war sie kongruent mit Wolbachia-Infektionen. Zusammenfassend kann gesagt werden, dass die tiefen phylogenetischen Aufspaltungen, die zur Hypothese der Existenz von kryptischen Arten bei beiden Phengaris-Arten führten, das Ergebnis von Wolbachia-Infektionen sind, die bei beiden Arten möglicherweise seit Millionen von Jahren persistent bestehen. Alle weiteren phylogenetischen Aufspaltungen und populationsgenetischen Gruppierungen sind Ergebnis ihrer phylogeographischen, nacheiszeitlichen Geschichte.Objective of present dissertation is a phylogenetic and phylogeographic investigation by using COI gene sequences, nuclear microsatellites, and Wolbachia-screens to test for cryptic species and phylogeographic scenarios in protected butterfly species Phengaris teleius and P. nausithous. The analyses based on mitochondrial COI sequences have shown a deep split in both species, which is estimated to have happened between 0.65–1.97 million years ago. This phylogenetic split was not reflected in the nuclear microsatellite pattern, but was concordant with an infection with the bacterial endosymbiont Wolbachia in both species. In both species the remaining phylogeographic structure was largely consistent between mitochondrial and nuclear genomes. The main conclusion is that deep intraspecific divergences found in DNA barcode studies do not represent cryptic species but instead resulted by both, infection by Wolbachia and phylogeographic structure
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