Browsing by Author "Galea, Thomas"
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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.
- Conservation status of Apis mellifera ruttneri inferred from whole genome sequencesPublication . Pinto, M. Alice; Ariel Yadró, Carlos; Henriques, Dora; Zammit Mangion, Marion; Galea, Thomas; Farrugia, Dylan; Cilia, Giovanni; Noureddine, Adjlane; Rufino, José; Nanetti, Antonio; Martín-Hernández, RaquelApis mellifera ruttneri is the native honey bee subspecies from the Maltese islands (Malta, Comino and Gozo). This African-lineage subspecies is adapted to the harsh environmental conditions and to the limited forage season of these islands. For many years, it was considered highly hybridized, due to the large and sustained importation of foreign subspecies, especially A. m. ligustica, perceived by many beekeepers as superior or for commercial reasons. Recent studies based on morphometry and mitochondrial DNA have suggested the occurrence of A. m. ruttneri, particularly in the main island. Conservation initiatives and a breeding program have been developed, but to date its conservation status is not fully known. As part of the MEDIBEES project, here, over 50 A. m. ruttneri georeferenced colonies collected from across Malta, as well as 50 several reference subspecies (A. m. ligustica, A. m. siciliana, A. m. iberiensis, A. m. sahariensis, and A. m. intermissa) were whole genome sequenced. The population structure and admixture were assessed from genome-wide single nucleotide polymorphisms using model and distance based-methods. The results show varying levels of admixture proportions of A. m. ruttneri with C-lineage honey bees across Malta but also a shared ancestry with the honey bees of north Africa, consistent with the putative natural colonization from Africa in ancient times.
- Deciphering the variation in cuticular hydrocarbon profiles of six European honey bee subspeciesPublication . Rodríguez-León, Daniel Sebastián; Uzunov, Aleksandar; Costa, Cecilia; Elen, Dylan; Charistos, Leonidas; Galea, Thomas; Gabel, Martin; Scheiner, Ricarda; Pinto, M. Alice; Schmitt, ThomasThe Western honey bee (Apis mellifera) subspecies exhibit local adaptive traits that evolved in response to the different environments that characterize their native distribution ranges. An important trait is the cuticular hydrocarbon (CHC) profile, which helps to prevent desiccation and mediate communication. We compared the CHC profiles of six European subspecies (A. m. mellifera, A. m. carnica, A. m. ligustica, A. m. macedonica, A. m. iberiensis, and A. m. ruttneri) and investigated potential factors shaping their composition. We did not find evidence of adaptation of the CHC profiles of the subspecies to the climatic conditions in their distribution range. Subspecies-specific differences in CHC composition might be explained by phylogenetic constraints or genetic drift. The CHC profiles of foragers were more subspecies-specific than those of nurse bees, while the latter showed more variation in their CHC profiles, likely due to the lower desiccation stress exerted by the controlled environment inside the hive. The strongest profile differences appeared between nurse bees and foragers among all subspecies, suggesting an adaptation to social task and a role in communication. Foragers also showed an increase in the relative amount of alkanes in their profiles compared to nurses, indicating adaptation to climatic conditions.
- Exploiting the mitogenomes of apis mellifera subspecies to develop an authentication tool to verify the entomological origin of mediterranean honeysPublication . Honrado, Mónica; Henriques, Dora; Santos, Joana; Yadró Garcia, Carlos A.; Martín-Hernández, Raquel; Nanetti, Antonio; González, Amelia Virginia; Al Shagour, Banan; Hosri, Chadi; Farrugia, Dylan; Giovanni, Cilia; Zammit Mangion, Marion; Muz, Mustafa Necati; Haddad, Nizar; Galea, Thomas; Haider, Yamina; Obeidat, Wisam; Aglagane, Abdessamad; Arab, Alireza; Varnava, Andri; Eissa, Asmaa Anwar; Muz, Dilek; Hatjina, Fani; Lamghari, Fouad; Arruda, James; Caristos Caristos, Leonidas; Pinto, M. Alice; Amaral, Joana S.Honey is highly susceptible to adulteration. Currently, the assessment of its geographical origin remains one of the most difficult tasks, which is typically performed by melyssopalynology. Recently, the attention has shifted towards indirect approaches such as the entomological origin based on geographical distribution patterns of honey bee subspecies. Although queens’ trade has impacted the natural subspecies distribution, honeys produced with autochthonous bees or bearing a Protected Designation of Origin specifying the producing honey bee subspecies, offer a unique avenue for authentication. In the MEDIBEES project, we aim to develop a DNA-metabarcoding approach to authenticate honey's entomological origin focusing on mitochondrial lineages A, M, C, and O. To achieve this goal, the DNA from 1251 honey bees representing 16 subspecies (A.m. sahariensis, A.m. intermissa, A.m. siciliana, A.m. ruttneri, A.m. iberiensis, A.m. ligustica, A.m. macedonica, A.m. adami, A.m. cecropia, A.m. cypria, A.m. caucasia, A.m. meda, A.m. anatoliaca, A.m. syriaca, A.m. jemenitica, A.m. lamarcki) was extracted and the whole genome sequenced. From those, 740 mitogenomes were assembled using the MitoZ software. The quality of the assembled mitogenome was assessed by aligning all the sequences using MEGA and 348 samples were deleted. Finally, a phylogenetic analysis was conducted to eliminate non-local subspecies, resulting in a total of 326 mitogenomes. This dataset was used for calculating the fixation index (FST) pairwise values, and a sliding window of 400bp was used to identify single nucleotide polymorphisms that effectively differentiate (FST>0.98) the four lineages, enabling the identification of promising regions for primer design. In this study, three regions were identified that discriminate the four maternal lineages while showing an appropriate length for metabarcoding, namely in the COI, ND1 gene, and CYTB genes.
- General beekeeping practices and main stressors identified by beekeepers in the MediterraneanPublication . Nanetti, Antonio; Martín-Hernández, Raquel; Zammit Mangion, Marion; Alice Pinto, M.; Farrugia, Dylan; Zammit Mangion, Rachel; Noureddine, Adjlane; Eissa, Asmaa Anwar; Cilia, Giovanni; Daour, Ahmad Yousef; Garrido, Claudia; Haddad, Nizar; Henriques, Dora; Hosri, Chadi; Muz, Mustafa Necati; Sagastume, Soledad; Galea, Thomas; Medibees ConsortiumBeekeeping is an ecologically and economically important activity in the Mediterranean that is increasingly under threat from a combination of factors. In the MEDIBEES (Monitoring the Mediterranean honey bee subspecies and their resilience to climate change for the improvement of sustainable agro-ecosystems) PRIMA project we aim to identify honey bees that show resilience to stressors associated with climate change. An important first step in our work was to establish baseline data of practices in the region through the administering of a questionnaire on the beekeeping practices. Over 1022 responses were received from beekeepers in Algeria, Egypt, Jordan, Italy, Lebanon, Malta, Spain, Portugal and Turkey. Beekeeping was overwhelmingly male dominated (ratio 9:1) and practiced largely by the middle-aged (mainly between 40-50 years). The majority of beekeepers reported having 10-50 boxes with the exceptions of Algeria and Jordan where the majority reported keeping more than 100 hive boxes. Across the Mediterranean the Langstroth hive box was most commonly used. Despite the perception of migratory beekeeping being frequently practiced, only Lebanon and Turkey reported significant levels of transhumance (>50.0 and 70.0% of beekeepers respectively). 51.2% of beekeepers reported practicing queen rearing with the majority of these (51.4%) reporting re-queening their colonies every 2 years. Interestingly, the majority of all beekeepers agreed with the statement that their native honey bee is endangered where pesticide use, lack of adequate forage and parasite infestations such as the Varroa mite were repeatedly cited as causing the greatest losses to honey bees in general. Climate change and urbanisation were also linked with colony losses by causing habitat loss. Supplementary feeding was reported to be an integral part of beekeeping in this region, with beekeepers reporting using between 0-5kg, closely followed by 6-10 kg of additional sugars.
- Maternal origin of honeybee (Apis mellifera) colonies from across EuropePublication . Lopes, Ana; Costa, Maíra; Tounakti, Sahar; Henriques, Dora; Quaresma, Andreia; Yadró Garcia, Carlos A.; Albo, Alexandre; Blažytė-Čereškienė, Laima; Broodschneider, Robert; Brusbardis, Valters; Carreck, Norman L.; Charistos, Leonidas; Chlebo, Robert; Coffey, Mary F.; Danneels, Ellen; Dobrescu, Constantin; Filipi, Janja; Gajda, Anna; Galea, Thomas; Gratzer, Kristina; Hatjina, Fani; Johannesen, Jes; Körmendy-Rácz, János; Kovačić, Marin; Preben, Kristiansen; Martikkala, Maritta; Martín-Hernández, Raquel; Pietropaoli, Marco; Poirot, Benjamin; Radev, Zheko; Raudmets, Aivar; Douarre, Vincent; Rodriguez-Flores, Maria Shantal; Roessink, Ivo; Ivana, Maja; Škerl, Maja Ivana Smodiš; Titera, Dalibor; Steen, Jozef van der; Varnava, Andri; Vejsnæs, Flemming; Webster, Matthew T.; Graaf, Dirk C.; Pinto, M. AliceWorldwide commercial beekeeping poses a threat to the native origin of the honeybee (Apis mellifera), with beekeepers favouring subspecies of Eastern European C-lineage ancestry, due to their docile behaviour and high honey production traits. In many parts of western and northern Europe, queens of Western European M-lineage ancestry have been massively replaced by queens of C-lineage ancestry, and this has led to the development of conservation programs aiming at recovering native lines. The maternally-inherited mitochondrial DNA (mtDNA), particularly the intergenic region tRNAleu-cox2, has been the marker of choice for assessing honey bee variation at large geographical scales. Herein, we will show the results of the mtDNA analysis of over 850 colonies collected across 28 European countries. These samples were subjected to DNA extraction, followed by PCR, and Sanger sequencing. The analysis of the sequences was conducted in Mega 11. The results indicated that, apart from Portugal, Spain, and the conservation centres in France and Denmark, where the colonies exhibited African or M haplotypes, the remaining countries are dominated by colonies of C-lineage maternal ancestry. In conclusion, this unprecedented mtDNA analysis conducted across Europe underscores the worrying dominance of C-lineage genetic variation, highlighting the urgent need for strategic conservation efforts to preserve the native genetic diversity of Apis mellifera.