THE INCIDENCE OF POTATO VIRUS Y (NECROTIC STRAINS) IN SEED POTATO GROWN IN SEVERAL ROMANIAN COUNTIES (PRELIMINARY STUDIES)

Protective measures of culture against Potato Virus Y necrotic strains (PVYN) infections, diagnosis and control of this pathogen play an important role in potato seed production technology and multiplication. Also, the choice of resistant varieties to the PVYN infection could be one of the measures recommended for farmers and producers. Surveys during 2 years (2014, 2015), in five main seed potato growing areas of Romania (Brasov, Covasna, Harghita, Cluj, Suceava), for 10 varieties (Christian, Roclas., Riviera, Carrera, Bellarosa, Jelly, Desiree, Red Fantasy, Hermes and Red Lady), revelead significant differences in PVYN incidence.The tests confirmed the PVYN presence in all the regions, with high prevalence of this virus especially for the cultivars Hermes and Carrera and very low spread for for the cultivars the cultivars the cultivars the cultivars the cultivars the cultivars Riviera and Christian

What is the main driver of ageing in long-lived winter honeybees : antioxidant enzymes, innate immunity, or vitellogenin?

Senescence or ageing in invertebrates is only partly unscrambled. Up to now five different theories deal with explaining the biology of ageing. Most likely physiology, genetic predestination and the impact of the environment form the image of ageing in individuals and groups. Social insects, especially the honeybee Apis mellifera, present the best model system to study developmentally related ageing, because high phenotypic plasticity makes the worker caste useful to dissolve remaining questions. Here, we used long-lived winter honeybee workers and measured transcriptional changes of 14 antioxidative enzymes, immunity and ageing-related (Insulin/insulin-like growth factor signalling-pathway) genes at two time points during hibernation. Additionally, the bees received a bacterial infection to see ageing and infection associated immunity changes. Gene expression levels for each group of target genes revealed that ageing had a much higher impact than the bacterial infections, notably for immunity related genes. Antimicrobial peptide and antioxidative enzyme genes were significantly up-regulated in aged worker honeybees independent of bacterial infections. Vitellogenin and IlP-1, known ageing markers, were contrary regulated with increasing vitellogenin levels during ageing. The increased antioxidative enzyme and antimicrobial peptide gene expression may have a positive and also protective effect during ageing in hibernating worker honeybees.http://biomedgerontology.oxfordjournals.org/hb201

Unity in defence: honeybee workers exhibit conserved molecular responses to diverse pathogens

This is the final version of the article. Available from the publisher via the DOI in this record.Background: Organisms typically face infection by diverse pathogens, and hosts are thought to have developed specific responses to each type of pathogen they encounter. The advent of transcriptomics now makes it possible to test this hypothesis and compare host gene expression responses to multiple pathogens at a genome-wide scale. Here, we performed a meta-analysis of multiple published and new transcriptomes using a newly developed bioinformatics approach that filters genes based on their expression profile across datasets. Thereby, we identified common and unique molecular responses of a model host species, the honey bee (Apis mellifera), to its major pathogens and parasites: the Microsporidia Nosema apis and Nosema ceranae, RNA viruses, and the ectoparasitic mite Varroa destructor, which transmits viruses. Results: We identified a common suite of genes and conserved molecular pathways that respond to all investigated pathogens, a result that suggests a commonality in response mechanisms to diverse pathogens. We found that genes differentially expressed after infection exhibit a higher evolutionary rate than non-differentially expressed genes. Using our new bioinformatics approach, we unveiled additional pathogen-specific responses of honey bees; we found that apoptosis appeared to be an important response following microsporidian infection, while genes from the immune signalling pathways, Toll and Imd, were differentially expressed after Varroa/virus infection. Finally, we applied our bioinformatics approach and generated a gene co-expression network to identify highly connected (hub) genes that may represent important mediators and regulators of anti-pathogen responses. Conclusions: Our meta-analysis generated a comprehensive overview of the host metabolic and other biological processes that mediate interactions between insects and their pathogens. We identified key host genes and pathways that respond to phylogenetically diverse pathogens, representing an important source for future functional studies as well as offering new routes to identify or generate pathogen resilient honey bee stocks. The statistical and bioinformatics approaches that were developed for this study are broadly applicable to synthesize information across transcriptomic datasets. These approaches will likely have utility in addressing a variety of biological questions.This article is a joint effort of the working group TRANSBEE and an outcome of two workshops kindly supported by sDiv, the Synthesis Centre for Biodiversity Sciences within the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, funded by the German Science Foundation (FZT 118). New datasets were performed thanks to the Insect Pollinators Initiative (IPI grant BB/I000100/1 and BB/I000151/1), with participation of the UK-USA exchange funded by the BBSRC BB/I025220/1 (datasets #4, 11 and 14). The IPI is funded jointly by the Biotechnology and Biological Sciences Research Council, the Department for Environment, Food and Rural Affairs, the Natural Environment Research Council, the Scottish Government and the Wellcome Trust, under the Living with Environmental Change Partnershi

Juvenile hormone pathway in honey bee larvae:a source of possible signal molecules for the reproductive behavior of Varroa destructor

Abstract The parasitic mite Varroa destructor devastates honey bee (Apis mellifera) colonies around the world. Entering a brood cell shortly before capping, the Varroa mother feeds on the honey bee larvae. The hormones 20‐hydroxyecdysone (20E) and juvenile hormone (JH), acquired from the host, have been considered to play a key role in initiating Varroa’s reproductive cycle. This study focuses on differential expression of the genes involved in the biosynthesis of JH and ecdysone at six time points during the first 30 hr after cell capping in both drone and worker larvae of A. mellifera. This time frame, covering the conclusion of the honey bee brood cell invasion and the start of Varroa’s ovogenesis, is critical to the successful initiation of a reproductive cycle. Our findings support a later activation of the ecdysteroid cascade in honey bee drones compared to worker larvae, which could account for the increased egg production of Varroa in A. mellifera drone cells. The JH pathway was generally downregulated confirming its activity is antagonistic to the ecdysteroid pathway during the larva development. Nevertheless, the genes involved in JH synthesis revealed an increased expression in drones. The upregulation of jhamt gene involved in methyl farnesoate (MF) synthesis came into attention since the MF is not only a precursor of JH but it is also an insect pheromone in its own right as well as JH‐like hormone in Acari. This could indicate a possible kairomone effect of MF for attracting the mites into the drone brood cells, along with its potential involvement in ovogenesis after the cell capping, stimulating Varroa’s initiation of egg laying

The genotype of potato variety plays an important role for the genetic constitution of somatic hybrids: Solanum tuberosum + late blight resistant S. bulbocastanum

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What Is the Main Driver of Ageing in Long-Lived Winter Honeybees: Antioxidant Enzymes, Innate Immunity, or Vitellogenin?

Senescence or ageing in invertebrates is only partly unscrambled. Up to now five different theories deal with explaining the biology of ageing. Most likely physiology, genetic predestination and the impact of the environment form the image of ageing in individuals and groups. Social insects, especially the honeybee Apis mellifera, present the best model system to study developmentally related ageing, because high phenotypic plasticity makes the worker caste useful to dissolve remaining questions. Here, we used long-lived winter honeybee workers and measured transcriptional changes of 14 antioxidative enzymes, immunity and ageing-related (Insulin/insulin-like growth factor signalling-pathway) genes at two time points during hibernation. Additionally, the bees received a bacterial infection to see ageing and infection associated immunity changes. Gene expression levels for each group of target genes revealed that ageing had a much higher impact than the bacterial infections, notably for immunity related genes. Antimicrobial peptide and antioxidative enzyme genes were significantly up-regulated in aged worker honeybees independent of bacterial infections. Vitellogenin and IlP-1, known ageing markers, were contrary regulated with increasing vitellogenin levels during ageing. The increased antioxidative enzyme and antimicrobial peptide gene expression may have a positive and also protective effect during ageing in hibernating worker honeybees.http://biomedgerontology.oxfordjournals.org/hb201