Browsing by Author "Le Conte, Yves"
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- BeeHeal: promoting bee health for sustainable agriculturePublication . Martín-Hernández, Raquel; Lopes, Ana; Chevjanovsky, Nor; Dalmon, Anne; Higes, Mariano; Le Conte, Yves; Pinto, M. Alice; Reyes-Carreño, Maritza; Soroker, VictoriaDuring the last years there is an alarming increase in the collapse of honeybee colonies (Apis mellifera) where bee parasites and pathogens like Varroa destructor mites, the microsporidia Nosema ssp. and viruses have played the leading role. Colony decline might compromise not only food security but also present and future income to the growers. Hence, four institutions from Mediterranean area have joined forces to put toghether a project entitled, “BEEHEAL: Promoting bee health for sustainable agriculture”. BEEHEAL is a collaborative research between Centro de Investigación Apícola y Agroambiental de Marchamalo - CAR (Spain), Centre de recherche Provence-Alpes-Côte d’Azur Unité: Abeilles et Environnement - INRA (France), Agricultural Research Organization, The Volcani Center - ARO (Israel) and Mountain Research Center (CMO), Polytechnic Institute of Bragança (Portugal). The aim of this project is to determine the phenology and interaction of the microsporidia Nosema ceranae and viruses including acute bee paralysis virus (ABPV), Israeli acute paralysis virus (IAPV), Black queen cell virus (BQCV) Chronic bee paralysis virus (CBPV) and Deformed wing virus (DWV), in Spain, France, Portugal and Israel. The findings of this project, which involves an active and unique cooperation among partners representing Mediterranean countries which encompasses a wide range of environmental and beekeeping management conditions, will contribute to ameliorate the damage caused by the expansion of N. ceranae through a rational implementation of existing treatments to avoid emergence of synergistic pathogens that accelerate colony collapse compromising food security. This project started at 2017 and it will end in 2020. BEEHEAL is funded through the ARIMNet2 (2016) Call by the following funding agencies: INIA (Spain), ANR (France), MOARD (Israel), and FCT (Portugal). This presentation will detail the tasks that are ongoing in the BEEHEAL project.
- Beeheal: standardization of laboratory methods for sample processing, nucleic acids extraction and PCR for microsporidia and viruses analysisPublication . Martín-Hernández, Raquel; Benito, M.; Chejanovsky, Nor; Le Conte, Yves; Dalmon, Anne; Higes, Mariano; Pinto, M. Alice; Reyes-Carreño, Maritza; Soroker, VictoriaBEEHEAL is a project designed to determine the phenology and interaction of Nosema ceranae and viruses in four Mediterranean countries: Spain, France, Portugal and Israel, including some territories where Varroa destructor is not present (Azores and Ouessant islands). This will allow us to study and compare the interactions between pathogens in a wide range of hosts, beekeeping and climatic conditions. The honey bee samples collected along the year in the different countries will be analysed for pathogens in three laboratories. This requires a standardization of methods to compare the results in order to assign the effect of every variable in a reliable way. To that end, the participating laboratories have been working together to establish the sampling methodology, the conservation of the samples, the nucleic acids extraction and the PCR analysis. We analyzed the sample processing for nucleic acid extraction on TE buffer (with or without Proteinase K), CTAB buffer or commercial kits (Qiagen). The maceration of bees (either individually or in composite samples) in TE buffer and posterior incubation at 96ºC for 20 minutes showed a good sensibility level and good value for N. ceranae DNA extraction. This method also allowed the conservation of RNA at -80ºC for a month in the TE solution for later RNA extraction. A joint protocol for sample processing, DNA and RNA extraction and PCR analysis has been developed but adjusted to the particular conditions and equipment of each laboratory. The standardization of methods to be implemented by each participating laboratory will avoid the biases on conclusions based on the diverse methods applied.
- Complex population structure and haplotype patterns in the Western European honey bee from sequencing a large panel of haploid dronesPublication . Wragg, David; Eynard, Sonia E.; Basso, Benjamin; Canale‐Tabet, Kamila; Labarthe, Emmanuelle; Bouchez, Olivier; Bienefeld, Kaspar; Bieńkowska, Małgorzata; Costa, Cecilia; Gregorc, Aleš; Kryger, Per; Parejo, Melanie; Pinto, M. Alice; Bidanel, Jean‐Pierre; Servin, Bertrand; Le Conte, Yves; Vignal, AlainHoney bee subspecies originate from specific geographical areas in Africa, Europe and the Middle East, and beekeepers interested in specific phenotypes have imported genetic material to regions outside of the bees' original range for use either in pure lines or controlled crosses. Moreover, imported drones are present in the environ-ment and mate naturally with queens from the local subspecies. The resulting ad-mixture complicates population genetics analyses, and population stratification can be a major problem for association studies. To better understand Western European honey bee populations, we produced a whole genome sequence and single nucleotide polymorphism (SNP) genotype data set from 870 haploid drones and demonstrate its utility for the identification of nine genetic backgrounds and various degrees of admixture in a subset of 629 samples. Five backgrounds identified correspond to sub-species, two to isolated populations on islands and two to managed populations. We also highlight several large haplotype blocks, some of which coincide with the position of centromeres. The largest is 3.6 Mb long and represents 21% of chromosome 11, with two major haplotypes corresponding to the two dominant genetic backgrounds identified. This large naturally phased data set is available as a single vcf file that can now serve as a reference for subsequent populations genomics studies in the honey bee, such as (i) selecting individuals of verified homogeneous genetic backgrounds as references, (ii) imputing genotypes from a lower-density data set generated by an SNP- chip or by low- pass sequencing, or (iii) selecting SNPs compatible with the re-quirements of genotyping chips.
- A composição química da feromona de alarme produzida pela abelha ibéria (Apis mellifera Iberiensis)Publication . Falcão, Soraia; Beslay, Dominique; Le Conte, Yves; Vilas-Boas, MiguelAs abelhas, como a maioria dos insectos sociais, produzem feromonas que controlam parcialmente muitos aspectos comportamentais e fisiológicos individuais e da colónia, como a resposta de alarme, orientação e o controlo da rainha sobre as obreiras [1]. A feromona de alarme é um dos elementos-chave no comportamento defensivo das abelhas. O “aroma a banana” destes voláteis, presentes na colmeia quando esta é perturbada, é facilmente reconhecido pelos apicultores. Esta feromona é constituída por uma mistura complexa de compostos produzidos maioritariamente nas glândulas de Koschevnikov e nas bainhas do ferrão, sendo acumulada na membrana setosa, o que permite uma rápida dispersão sempre que o ferrão é libertado. Mais de quarenta compostos foram já identificados, entre os quais compostos oxigenados, bastante voláteis, envolvidos na sinalização do alarme. Esta complexidade química cria uma assinatura única para esta feromona, sendo específica para cada tipo de abelha [2]. Neste trabalho pretendeu-se analisar a feromona de alarme emitida pelas obreiras da abelha ibérica (Apis mellifera iberiensis) procedendo-se à otimização do processo de extração e análise da feromona. Para isso, foram removidos e extraídos os aparelhos do ferrão de abelhas recolectoras capturadas à entrada de colónias de abelhas ibéricas provenientes de um apiário experimental situado em Nogueira (Bragança). Após a extração, efetuou-se a análise por cromatografia gasosa acoplada a espectrometria de massa (GC-MS) onde foram identificados cerca de 20 compostos, entre os quais o, álcool benzílico, o octanol, o 2-nonanol, acetato de isopentilo, o eicosenol, o 2-decenol e o ácido 9- octadecenóico, sendo estes últimos descritos pela primeira vez em feromonas de Apis mellifera. O acetato de isopentilo e o eicosenol são os principais responsáveis pelo desencadear da resposta ao comportamento de alarme.
- Epidemiology of the microsporidium nosema ceranae in four mediterranean countriesPublication . Jabal-Uriel, Clara; Barrios, Laura; Bonjour-Dalmon, Anne; Caspi-Yona, Shiran; Chejanovsky, Nor; Erez, Tal; Henriques, Dora; Higes, Mariano; Le Conte, Yves; Lopes, Ana; Meana, Aranzazu; Alice Pinto, M.; Teixeira, Amílcar; Reyes-Carreño, Maritza; Soroker, Victoria; Martín-Hernández, RaquelNosema ceranae is a highly prevalent intracellular parasite of honey bees’ midgut worldwide. This Microsporidium was monitored during a long-term study to evaluate the infection at apiary and intra-colony levels in six apiaries in four Mediterranean countries (France, Israel, Portugal, and Spain). Parameters on colony strength, honey production, beekeeping management, and climate were also recorded. Except for São Miguel (Azores, Portugal), all apiaries were positive for N. ceranae, with the lowest prevalence in mainland France and the highest intra-colony infection in Israel. A negative correlation between intra-colony infection and colony strength was observed in Spain and mainland Portugal. In these two apiaries, the queen replacement also influenced the infection levels. The highest colony losses occurred in mainland France and Spain, although they did not correlate with the Nosema infection levels, as parasitism was low in France and high in Spain. These results suggest that both the effects and the level of N. ceranae infection depends on location and beekeeping conditions. Further studies on host-parasite coevolution, and perhaps the interactions with other pathogens and the role of honey bee genetics, could assist in understanding the difference between nosemosis disease and infection, to develop appropriate strategies for its control.
- Feromonas emitidas pelas rainhas da abelha ibérica (Apis mellifera iberiensis): desenvolvimento de um sistema de recolha In Vivo por micro-extração em fase sólida (SPME)Publication . Falcão, Soraia; Le Conte, Yves; Vilas-Boas, MiguelAs feromonas são infoquímicos segregados pelas glândulas de um animal que estimulam uma resposta comportamental ou fisiológica em outro animal da mesma espécie [1]. São misturas complexas, capazes de induzir uma resposta em concentrações muito baixas. Podem ser altamente voláteis, com pesos moleculares baixos e de rápida difusão no ar ou menos voláteis, mais pesados, adsorvidos na superfície do corpo e passados por contato corporal [2]. Numa colónia de abelhas existem duas castas femininas, uma rainha e milhares de obreiras. A rainha, normalmente, a única fêmea reprodutora da colónia, é o fator regulador mais importante de uma colónia. Esta regulação é conseguida através das feromonas, produzidas em diferentes glândulas e emitidas como uma mistura complexa conhecida como o sinal da rainha. Este induz várias modificações fisiológicas e comportamentais nas abelhas obreiras que resultam na manutenção da homeostase da colónia através do estabelecimento da hierarquia social e da preservação da supremacia reprodutiva da rainha [2). Neste trabalho pretendeu-se analisar as feromomas emitidas in vivo pelas rainhas da abelha ibérica (Apis mellifera iberiensis). Para isso recorreu-se à técnica de micro-extração em fase sólida (SPME), por ser uma técnica versátil, precisa e rápida, baseada na adsorção dos voláteis numa fase de extração imobilizada sobre a superfície de uma fibra de sílica fundida. O trabalho foi realizado com colónias de abelhas ibéricas provenientes de um apiário experimental situado em Bragança. A criação de rainhas foi realizada seguindo métodos padrão de apicultura, método Doolitle [3]. Após a operculação dos alvéolos reais, estes foram transferidos para o laboratório, e mantidos a 35 ºC e 70% de humidade relativa. Após o nascimento as rainhas foram mantidas durante sete dias em gaiolas na companhia de abelhas ama, com alimentação artificial e água. Após esse período, procedeu-se à recolha de voláteis colocando a rainha num frasco âmbar de 50 ml. A fibra de SPME, protegida por uma rede metálica, foi introduzida no frasco, sendo a amostragem efectuada durante 15 min, com uma temperatura de 28 ºC e 50 % de humidade relativa. Foi usada uma fibra de polidimetilsiloxano/divinilbenzeno (Supelco SPME fiber 57326U). Após a recolha a fibra foi imediatamente colocada num aparelho de cromatografia gasosa acoplada a espectrometria de massa (GC/MS) e desorbida durante 5 min a 250 ºC em modo splitless. Esta técnica demonstrou ser adequada para recolher todos os compostos voláteis emitidos pela abelha, minimizando situações de stress da abelha.
- Interactions between prevalent pathogens of honeybees (Apis mellifera)Publication . Jabal-Uriel, Clara; Bonjour-Dalmon, Anne; Chejanovsky, Nor; Higes, Mariano; Le Conte, Yves; Lopes, Ana; Pinto, M. Alice; Reyes-Carreño, Maritza; Soroker, Victoria; Martín-Hernández, RaquelThe aim of the BEEHEAL project was to determine the phenology and interactions of the microsporidia Nosema ceranae and 5 highly prevalent and pathogenic honeybee viruses (DWV, BQCV, ABPV, IAPV and CBPV) in four Mediterranean countries: France, Israel, Portugal and Spain. The prevalence and phenology of these pathogens was monitored in four continental apiaries (one in each country) and three insular apiaries located on Ouessant Island (France) and on São Miguel and Santa Maria Islands (Portugal). Colonies were sampled during a 2-year study period, and honeybees were collected and analysed once every two months. Microsporidia detection was performed by conventional triplexPCR whereas viral loads were determined by RT-qPCR of the positive samples. Israel had the highest percentage of honeybees infected by Ǥ ” , followed by Spain, continental Portugal, and Ouessant, whereas the levels were the lowest in France mainland and it was not detected on the Portuguese Islands. The countries with the higher prevalence of viruses were France and Israel whereas the apiaries in Portugal and Spain had a lower percentage of colonies and individual honeybees infected by viruses. Moreover, CBPV was not detected in the latter countries. The viral load of colonies and honeybees coinfected with twoor more viruseswas positively correlated. Data analysedfrom all apiariestogether showed a negative correlation between the percentage of infected N. ceranae honeybees and the viral load. However, there was no correlation at the apiary level between N. ceranae and the viral load when analysed separately. Cross-tabulations showed a correlation in coinfection between N. ceranae with any of the three viruses: BQCV, IAPV and CBPV. In fact, honeybees coinfected by the microsporidia and one of these viruses had a higher viral load than honeybees infected only with the virus. This study showed that pathogen interactions differs greatly among countries and serves as a starting point for the development of epidemiological studies to unravel pathogen coinfections.
- Mitochondrial and nuclear diversity of colonies of varying origins: contrasting patterns inferred from the intergenic tRNAleu-cox2 region and immune SNPsPublication . Henriques, Dora; Lopes, Ana; Chejanovsky, Nor; Dalmon, Anne; Higes, Mariano; Jabal-Uriel, Clara; Le Conte, Yves; Reyes-Carreño, Maritza; Soroker, Victoria; Martín-Hernández, Raquel; Pinto, M. AliceIn this study, we gathered sequence data from the tRNAleu-cox2 intergenic mitochondrial (mtDNA) region concurrently with single nucleotide polymorphism (SNP) data from 91 loci of nuclear DNA (ncDNA). The data was obtained from 156 colonies sampled in six apiaries from four countries. The full dataset was analysed and discussed for genetic patterns with a focus on cytonuclear diversity and admixture levels.
- Nosema ceranae in Apis mellifera: a 12 years postdetection perspectivePublication . Martín-Hernández, Raquel; Bartolomé, Carolina; Chejanovsky, Nor; Le Conte, Yves; Dalmon, Anne; Dussaubat, Claudia; García-Palencia, Pilar; Meana, Aranzazu; Pinto, M. Alice; Soroker, Victoria; Higes, MarianoNosema ceranae is a hot topic in honey bee health as reflected by numerous papers published every year. This review presents an update of the knowledge generated in the last 12 years in the field of N. ceranae research, addressing the routes of transmission, population structure and genetic diversity. This includes description of how the infection modifies the honey bee’s metabolism, the immune response and other vital functions. The effects on individual honey bees will have a direct impact on the colony by leading to losses in the adult’s population. The absence of clear clinical signs could keep the infection unnoticed by the beekeeper for long periods. The influence of the environmental conditions, beekeeping practices, bee genetics and the interaction with pesticides and other pathogens will have a direct influence on the prognosis of the disease. This review is approached from the point of view of the Mediterranean countries where the professional beekeeping has a high representation and where this pathogen is reported as an important threat.
- Phenology of the Microsporidia Nosema ceranae in four mediterranean countriesPublication . Jabal-Uriel, Clara; Bonjour-Dalmon, A.; Chejanovsky, Nor; Higes, Mariano; Le Conte, Yves; Lopes, Ana; Pinto, M. Alice; Reyes-Carreño, Maritza; Soroker, Victoria; Martín-Hernández, RaquelThe presence and prevalence of the Microsporidia Nosema ceranae was assessed as part of the BEEHEAL project during a 2-year study period (2018-2019). Monitoring took place in six apiaries located in four Mediterranean continental apiaries: France, Israel, Portugal and Spain, and two insular apiaries located on Ouessant (France) and on São Miguel (Azores archipelago, Portugal). Besides honeybee sample collection every two months, parameters on colony strength, honey production, beekeeping management and climate were recorded. The pathogen was not detected on São Miguel Island during the study. Infection at the apiary level showed that most of the colonies were positive to N. ceranae except in mainland France, where the percentage of infected colonies was the lowest and it fluctuated, with an increase in August in both years. The percentage of infected honeybees per colony varied among apiaries, with Israel having the highest mean levels (32.39%). Colonies in Spain and Portugal showed a similar pattern with the highest levels of infection in April 2018. Ouessant Island had a high percentage of infected honeybees in 2018 and it decreased on 2019. Temperature was not correlated with N. ceranae infection, although high temperatures combined with high relative humidity were associated to high infection levels in Israel. Intra-colony percentage of infection was positively correlated with honeybee population when all apiaries were analysed together. Honey production was not related with N. ceranae infection. Regarding queen replacement, infection levels in spring 2019 in mainland Portugal and Spain decreased in those colonies that had replaced the queen the previous summer (August 2018). Colony mortality varied amo ng apiaries, with mainland France and Spain showing the highest colony losses (47.6% and 39.1%, respectively). However, this parameter was not correlated with the levels of infection. These results allowed to compare the N. ceranae phenology among different countries showing that the infection is dependent on many factors. This information could assist in the development of beekeeping management strategies.