Browsing by Author "Meixner, Marina D."
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- Authoritative subspecies diagnosis tool for European honey bees based on ancestry informative SNPsPublication . Momeni, Jamal; Parejo, Melanie; Nielsen, Rasmus O.; Langa, Jorge; Montes, Iratxe; Papoutsis, Laetitia; Farajzadeh, Leila; Bendixen, Christian; Căuia, Eliza; Charrière, Jean Daniel; Coffey, Mary F.; Costa, Cecilia; Dall'Olio, Raffaele; De la Rúa, Pilar; Dražić, Marica Maja; Filipi, Janja; Galea, Thomas; Golubovski, Miroljub; Gregorc, Aleš; Grigoryan, Karina; Hatjina, Fani; Ilyasov, Rustem; Ivanova, Evgeniya Neshova; Janashia, Irakli; Kandemir, Irfan; Karatasou, Aikaterini; Kekecoglu, Meral; Kezic, Nikola; Matray, Enikö Sz; Mifsud, David; Moosbeckhofer, Rudolf; Nikolenko, Alexei G.; Papachristoforou, Alexandros; Petrov, Plamen; Pinto, M. Alice; Poskryakov, Aleksandr V.; Sharipov, Aglyam Y.; Siceanu, Adrian; Soysal, M. Ihsan; Uzunov, Aleksandar; Zammit Mangion, Marion; Vingborg, Rikke; Bouga, Maria; Kryger, Per; Meixner, Marina D.; Estonba, AndoneWith numerous endemic subspecies representing four of its five evolutionary lineages, Europe holds a large fraction of Apis mellifera genetic diversity. This diversity and the natural distribution range have been altered by anthropogenic factors. The conservation of this natural heritage relies on the availability of accurate tools for subspecies diagnosis. Based on pool-sequence data from 2145 worker bees representing 22 populations sampled across Europe, we employed two highly discriminative approaches (PCA and FST) to select the most informative SNPs for ancestry inference. Results: Using a supervised machine learning (ML) approach and a set of 3896 genotyped individuals, we could show that the 4094 selected single nucleotide polymorphisms (SNPs) provide an accurate prediction of ancestry inference in European honey bees. The best ML model was Linear Support Vector Classifier (Linear SVC) which correctly assigned most individuals to one of the 14 subspecies or different genetic origins with a mean accuracy of 96.2% ± 0.8 SD. A total of 3.8% of test individuals were misclassified, most probably due to limited differentiation between the subspecies caused by close geographical proximity, or human interference of genetic integrity of reference subspecies, or a combination thereof. Conclusions: The diagnostic tool presented here will contribute to a sustainable conservation and support breeding activities in order to preserve the genetic heritage of European honey bees.
- Evaluation of suppressed mite reproduction (Smr) reveals potential for varroa resistance in european honey bees (apis mellifera l.)Publication . Mondet, Fanny; Parejo, Melanie; Meixner, Marina D.; Costa, Cecilia; Kryger, Per; Andonov, Sreten; Servin, Bertrand; Basso, Benjamin; Bieńkowska, Małgorzata; Bigio, Gianluigi; Căuia, Eliza; Cebotari, Valentina; Dahle, Bjørn; Dražić, Marica Maja; Hatjina, Fani; Kovačić, Marin; Kretavicius, Justinas; Lima, Ana S.; Panasiuk, Beata; Pinto, M. Alice; Uzunov, Aleksandar; Wilde, Jerzy; Büchler, RalphIn the fight against the Varroa destructor mite, selective breeding of honey bee (Apis mellifera L.) populations that are resistant to the parasitic mite stands as a sustainable solution. Selection initiatives indicate that using the suppressed mite reproduction (SMR) trait as a selection criterion is a suitable tool to breed such resistant bee populations. We conducted a large European experiment to evaluate the SMR trait in different populations of honey bees spread over 13 different countries, and representing different honey bee genotypes with their local mite parasites. The first goal was to standardize and validate the SMR evaluation method, and then to compare the SMR trait between the different populations. Simulation results indicate that it is necessary to examine at least 35 single-infested cells to reliably estimate the SMR score of any given colony. Several colonies from our dataset display high SMR scores indicating that this trait is present within the European honey bee populations. The trait is highly variable between colonies and some countries, but no major differences could be identified between countries for a given genotype, or between genotypes in different countries. This study shows the potential to increase selective breeding efforts of V. destructor resistant populations.
- Hinf-I digestion of cytochrome oxidase I region is not a diagnostic test for A-m. lamarckiiPublication . Kandemir, Irfan; Pinto, M. Alice; Meixner, Marina D.; Sheppard, Walter S.Restriction fragment length polymorphism of whole mitochondrial DNA or PCR amplified mtDNA regions are known to be useful in discriminating among honey bee lineages and also some individual subspecies. In this study, PCR-amplified fragments of cytochrome oxidase I (CO-I) and cytochrome B (Cyt B) of honey bees sampled from different countries (Cyprus, Turkey, Ethiopia, Syria and Egypt) were digested with Hinf I and Bgl II restriction enzymes, respectively. Eastern Europe and Mediterranean honey bee subspecies were separated by the Cyt B/Bgl II analysis, although Hinf I digestion of the CO-I region yielded much finer resolution within different honey bee lineages. Here we report that CO-I/Hinf-I is a discriminative test for the mitochondrial “O” lineage, rather than a diagnostic site for A. m. lamarckii.
- Standard methods for characterising subspecies and ecotypes of Apis melliferaPublication . Meixner, Marina D.; Pinto, M. Alice; Bouga, Maria; Kryger, Per; Ivanova, Evgeniya Neshova; Fuchs, StefanThe natural diversity of honey bees in Europe is eroding fast. A multitude of reasons lead to a loss of both genetic diversity and specific adaptations to local conditions. To preserve locally adapted bees through breeding efforts and to maintain regional strains in conservation areas, these valuable populations need to be identified. In this paper, we give an overview of methods that are currently available and used for recognition of honey bee subspecies and ecotypes, or that can be utilised to verify the genetic origin of colonies for breeding purposes. Beyond summarising details of morphometric, allozyme and DNA methods currently in use, we report recommendations with regard to strategies for sampling, and suggest methods for statistical data analysis. In particular, we emphasise the importance of reference data and consistency of methods between laboratories to yield comparable results.