Percorrer por autor "Elen, Dylan"
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- Conservation status of the endemic European Dark Honey Bee (Apis mellifera mellifera) in Belgium & NetherlandsPublication . Elen, Dylan; Malhotra, Anita; Henriques, Dora; Herremans, Mathijs; Pinto, M. Alice; Cross, PaulDue to past and present imports of Apis mellifera ligustica (Italian bees), Apis mellifera carnica (Carniolan bees) and the Buckfast bee (a hybrid strain) across its entire natural range, the European Dark Honey bee (Apis mellifera mellifera) is currently threatened with extinction by genetic pollution through hybridization. In the past, genomic research has shown the European Dark Honey bee was still present in the Belgian Chimay area and on the Dutch North Sea Isle of Texel. However, as the risk of beekeepers importing non-native honey bees into the area remains, which could rapidly threaten the genetic integrity of the endemic honey bee population, monitoring hybridization is a key element in conservation and breeding. Within the framework of the Flemish Beekeeping Programme, 246 honey bee colonies originating from the Belgian population of Chimay (108) and the Dutch North Sea island populations of Texel (6) and Terschelling (132) were sampled in autumn 2021 to identify pure European Dark Honey bee colonies with which to support the Flemish A. m. mellifera breeding activities. The population of Terschelling, which has not been studied before, was included because local beekeepers claimed their colonies looked and behaved like European Dark Honey bees. Of each sampled honey bee colony 10 worker bees were used for this study, including measuring wing morphometrics (based on cubital index, discoidal shift angle and hantal index) and estimating the extent of C-lineage introgression in the ncDNA by applying a custom-tailored SNP genotype assay. Q-values for most sampled honey bee colonies were above 90% for M-lineage: 85 out of 108 colonies for Chimay; 106 out of 132 colonies for Terschelling and all 6 colonies for Texel. Both the populations of Chimay and Texel seem to be spared from intense hybridization over the past decades, whilst a novel remnant population of the European Dark Honey bee was found on the Isle of Terschelling. The correlation between wing morphometrics and molecular data was significant but very weak (Spearman r = 0.20, p = 0.002), indicating the SNP genotype assay is a more valuable tool for assisting in breeding and conservation activities.
- 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.
- DeepWings: a machine learning tool for identification of honey bee subspeciesPublication . Ariel Yadró, Carlos; Rodrigues, Pedro João; Adam, Tofilski; Elen, Dylan; McCormack, Grace P.; Henriques, Dora; Pinto, M. AliceDeepWings© is a software that uses Machine Learning for fully automated identification of Apis mellifera subspecies based on wing geometric morphometrics (WGM). Here, we examined the performance of DeepWings© under realistic conditions by processing 14,782 wing images with varying quality and produced by different operators. These images represented 2,593 colonies covering the native ranges of A. m. iberiensis (Portugal, Spain and historical introduction in the Azores), A. m. mellifera (Belgium, France, Ireland, Poland, Russia, Sweden, Switzerland, UK) and A. m. carnica (Croatia, Hungary, Romania). The classification probability obtained for the colonies was contrasted with the endemic subspecies distribution. Additionally, the association between WGM classification and that inferred from microsatellites and SNPs was evaluated for 1,214 colonies. As much as 94.4% of the wings were accepted and classified by DeepWings©. In the Iberian honey bee native range, 92,6% of the colonies were classified as A. m. iberiensis with a median probability of 91.88 (IQR = 22.52). In the Azores, 85.7% of colonies were classified as A. m. iberiensis, with a median probability of 84.16 (32.40). In the Dark honey bee native range, 41.1 % of the colonies were classified as A. m mellifera with a median probability of 99.36 (8.02). The low percentage of colonies matching the native subspecies was mainly due to the low values registered in Avignon (20.0%), Poland (32.9%), and Wales (41.2%). In contrast, most of the colonies analyzed in other locations of the native range of A. m. mellifera matched this subspecies: Belgium (100.0%), Groix (63.9%), Ouessant (72.7%), Ireland (78.0%), Russia (96.2%), Sweden (84.2%) and Switzerland (55.6%). In the colonies from Croatia, Hungary, and Romania, 88.0% of the samples were classified as A. m. carnica, with a median probability of 98.49 (6.76). The association between WGM and molecular data was highly significant but not very strong (Spearman r = 0.31, p < 0.0001). A good agreement between morphological and molecular methods was registered in samples originating from highly conserved M-lineage populations whereas in populations with historical records of foreign queen importations the agreement was weaker. In general, DeepWings© showed good performance when tested under realistic conditions. It is a valuable tool that can be used not only for honey bee breeding and conservation but also for research purposes.
- The Welsh dark bee (Apis mellifera mellifera) is not extinctPublication . Elen, Dylan; Henriques, Dora; Pinto, M. Alice; Malhotra, Anita; Cross, PaulDue to past and present imports of Apis mellifera ligustica (Italian bees), Apis mellifera carnica (Carniolan bees) and the English Buckfast bee (a hybrid strain) across its entire natural range, Apis mellifera mellifera is now threatened with extinction by genetic pollution through hybridization. Whilst the status of remnant A. m. mellifera populations is well documented on the European mainland, few studies have been undertaken to identify surviving populations on the British Isles. A few A. m. mellifera stocks are thought to persist in Scotland and the southwest of England and recently, Ireland might appear to contain multiple non-hybridized A. m. mellifera populations. 163 young worker bees, representing 121 colonies from across Wales, were genetically screened in an attempt to identify remnant A. m. mellifera stocks, as part of a conservation breeding program. Recent studies have demonstrated that honey bees of local origin have significantly higher survival chances than honey bees of non-local origin due to their adaptation to their local environment, suggesting that conservation of locally adapted honey bees is a logistical and practical possibility to develop sustainable apiculture. Within this survey, we made use of a custom-tailored SNP genotype assay to estimate the extent of C lineage introgression in the ncDNA as well as sequencing of the tRNAleucox2 intergenic region of the mtDNA to check for the ancestry of the tested colonies
- Using the software DeepWings© to classify honey bees across europe through wing geometric morphometricsPublication . Garcia, Carlos A.Y.; Rodrigues, Pedro João; Tofilski, Adam; Elen, Dylan; McCormack, Grace P.; Oleksa, Andrzej; Henriques, Dora; Ilyasov, Rustem; Kartashev, Anatoly; Bargain, Christian; Fried, Balser; Pinto, M. AliceDeepWings© is a software that uses machine learning to automatically classify honey bee subspecies by wing geometric morphometrics. Here, we tested the five subspecies classifier (A. m. carnica, Apis mellifera caucasia, A. m. iberiensis, Apis mellifera ligustica, and A. m. mellifera) of DeepWings© on 14,816 wing images with variable quality and acquired by different beekeepers and researchers. These images represented 2601 colonies from the native ranges of the M-lineage A. m. iberiensis and A. m. mellifera, and the C-lineage A. m. carnica. In the A. m. iberiensis range, 92.6% of the colonies matched this subspecies, with a high median probability (0.919). In the Azores, where the Iberian subspecies was historically introduced, a lower proportion (85.7%) and probability (0.842) were observed. In the A. m mellifera range, only 41.1 % of the colonies matched this subspecies, which is compatible with a history of C-derived introgression. Yet, these colonies were classified with the highest probability (0.994) of the three subspecies. In the A. m. carnica range, 88.3% of the colonies matched this subspecies, with a probability of 0.984. The association between wing and molecular markers, assessed for 1214 colonies from the M-lineage range, was highly significant but not strong (r = 0.31, p < 0.0001). The agreement between the markers was influenced by C-derived introgression, with the best results obtained for colonies with high genetic integrity. This study indicates the good performance of DeepWings© on a realistic wing image dataset.
- Virus prevalence in egg samples collected from naturally selected and traditionally managed honey bee colonies across europePublication . Bouuaert, David Claeys; De Smet, Lina; Brunain, Marleen; Dahle, Bjørn; Blacquiere, Tjeerd; Dalmon, Anne; Dezmirean, Daniel; Elen, Dylan; Filipi, Janja; Giurgiu, Alexandru; Gregorc, Aleš; Kefuss, John; Locke, Barbara; Miranda, Joachim; Oddie, Melissa; Panziera, Delphine; Parejo, Melanie; Pinto, Maria Alice; Graaf, Dirk C.Monitoring virus infections can be an important selection tool in honey bee breeding. A recent study pointed towards an association between the virus-free status of eggs and an increased virus resistance to deformed wing virus (DWV) at the colony level. In this study, eggs from both naturally surviving and traditionally managed colonies from across Europe were screened for the prevalence of different viruses. Screenings were performed using the phenotyping protocol of the ‘suppressed in ovo virus infection’ trait but with qPCR instead of end-point PCR and a primer set that covers all DWV genotypes. Of the 213 screened samples, 109 were infected with DWV, 54 were infected with black queen cell virus (BQCV), 3 were infected with the sacbrood virus, and 2 were infected with the acute bee paralyses virus. It was demonstrated that incidences of the vertical transmission of DWV were more frequent in naturally surviving than in traditionally managed colonies, although the virus loads in the eggs remained the same. When comparing virus infections with queen age, older queens showed significantly lower infection loads of DWV in both traditionally managed and naturally surviving colonies, as well as reduced DWV infection frequencies in traditionally managed colonies. We determined that the detection frequencies of DWV and BQCV in honey bee eggs were lower in samples obtained in the spring than in those collected in the summer, indicating that vertical transmission may be lower in spring. Together, these patterns in vertical transmission show that honey bee queens have the potential to reduce the degree of vertical transmission over time.