New paper on effect of Varroa vector on honey bee viromes !

vincentdoublet

Well… that paper is not very new as it was published a few weeks ago, but now the winter semester is over, I can take the time to advertise it here.

So what is it about?

Back in the 50’s, the parasitic mite Varroa destructor managed to jump from its native host, the Eastern honeybee Apis cerana, to a new host, the Western honeybee Apis mellifera. Following that host jump, international trades of Western honeybees spread for decades the parasitic mite all over the globe.

Quickly, beekeepers around the world realized that after this invasion bees were suffering from a disease leading to worker body and wing deformities. The causing agent: deformed wing virus, or DWV. A RNA virus that quickly evolved into a vector-borne pathogen.

But is DWV the only virus vectored by Varroa?

To answer that question, we measured virus loads and prevalence in honeybees collected beyond and behind the invasion front of the mite, over 3 continents. This was possible as remote islands and valleys remained mite-free for years.

With 654 samples in total, we showed that Varroa invasion changed DWV epidemiology, as expected. We also found that presence of the mite increased black queen cell virus (BQCV) prevalence and loads, chronic bee paralysis virus (CBPV) and sacbrood virus (SBV) prevalence, and Lake Sinai virus-2 (LSV-2) loads. The PCA below illustrates nicely how this disease vector influenced its host virome.

Eventually, this shows that beyond DWV, other important viruses experienced a change following the invasion of the mite, and these may also deserve great attention.

You may find the paper here: https://royalsocietypublishing.org/doi/10.1098/rsos.231529

Sage Policy Profiles

vincentdoublet

I came across this new online tool, that everyone can use for free, where researchers can find in one click their citations in policy documents.

See here: https://policyprofiles.sagepub.com

This is proposed by Sage Publishing, under the name Sage Policy Profiles.

I am happy to see that my research on bee health has been well cited, in 25 documents, mainly from Europe, but also North America and Asia, or intergovernmental organizations such as IPBES documents.

You can see my profile here:

https://policyprofiles.sagepub.com/profile/502/vincent-doublet

New paper on disease tolerance in Drosophila… with journal cover!

vincentdoublet

Defense strategies against pathogens can be categorized into disease resistance, the host mechanisms involved in the reduction of pathogen, or disease tolerance, where hosts do not exert a direct impact on pathogens but instead limit its cost on health and fitness.

In Drosophila melanogaster, genetic variation in mortality following infection with Drosophila C virus (DCV) is driven by large effect polymorphisms in the restriction factor pastrel (pst). However, it is unclear if pst contributes to disease tolerance.

In this work, we described genetic variation in disease tolerance using flies carrying either a susceptible (S) or resistant (R) pst allele, across a range of DCV doses. We found among-line variation in fly survival, viral load and disease tolerance measured both as the ability to maintain survival (mortality tolerance) and reproduction (fecundity tolerance). Besides, we found that the pst gene is associated with general vigour in the absence of infection and confirm its role in reducing DCV titres during infection.

For this paper, co-led by Megan Kutzer and Vanika Gupta, Kyriaki Neophytou and myself analyzed gene expression variations across fly lines, and showed pst affects the expression of genes involved in disease tolerance, namely upd3 and G9a.

This work represents one of the first descriptions of genetic variation in mortality tolerance and fecundity tolerance in a viral infection of invertebrates.

The reference:

Kutzer MAM, Gupta V, Neophytou K, Doublet V, Monteith KM, Vale PF (2023) Intraspecific genetic variation in host vigour, viral load and disease tolerance during Drosophila C virus infection. Open Biology. 13:230025. https://doi.org/10.1098/rsob.230025

And the journal cover:

New paper on disease transmission in bees

vincentdoublet

See our new paper published this month in the Philosophical Transactions of the Royal Society B.

We followed bee viruses over a year in UK farms involved at different levels in a pollinator conservation program, to find that wildflower strips did not act as transmission hubs for viruses, but helped reducing the prevalence of Deformed wing virus (DWV), likely through dilution effect, playing an unintended role in pollinator conservation.

Interestingly, we found that both viruses DWV and Acute bee paralysis virus (ABPV) to show different evolutionary history and response to agricultural practices, highlighting the importance of understanding single viral species epidemiology when developing disease transmission mitigation strategies.

Our results suggest that restoration and conservation measures for pollinators, in addition to increasing biodiversity and abundance of insect species, can reduce the prevalence and load of key viral pathogens of pollinators, both managed (honeybees) and wild (e.g. bumblebees).

This article is part of the theme issue ‘Infectious disease ecology and evolution in a changing world’ that you can find here: https://royalsocietypublishing.org/toc/rstb/2023/378/1873

And here is the paper:

Manley R, Doublet V, Wright ON, Doyle T, Refoy I, Hedges S, Pascall D, Carvell C, Brown MJF, Wilfert L (2023) Conservation measures or hotspots of disease transmission? Agri-environment schemes can reduce disease prevalence in pollinator communities. Philosophical Transactions of the Royal Society B, 378: 20220004. doi:10.1098/rstb.2022.0004

New project funded

vincentdoublet

We will start a new project soon, thanks to the financial support of the Eva Crane Trust, to study the antiviral response of bees. I would like to thank the Trustees for selecting my project, up to £16,000. Matthias, a Master student of the University of Ulm, will soon start his experiments. More to come soon…

New paper!

vincentdoublet

Our last article has been published last week in Ecology and Evolution.


In this study, we tested how wildflower strips (WFS) can impact plant-pollinator networks. We found that increasing flower provision in 10 UK farms increases abundance of bees, and importantly, both flower density and flower species richness can increase the number of visiting pollinators.


We also found, as main result of our study, that sown flowers along field margins modify the structure of pollinator networks. In flower with higher flower diversity, we found networks with lower connectance and lower niche overlap. Our results suggest that careful design of WFS seed mixes may potentially reduce competition and disease transmission between bees -hypotheses that remain to be tested.


We also recommend to extend the use of wildflower strips into the crucial spring period, when bumble bee queen are establishing their colonies.


The reference:

Doublet V, Doyle T, Refoy I, Hedges S, Carvell C, Brown MJF, Wilfert L (2022) Increasing flower species richness in agricultural landscapes alters insect pollinator networks: implications for bee health and competition. Ecology and Evolution, 12(10): e9442. doi:10.1002/ece3.9442

New project funded by the DFG ! One PhD position available

vincentdoublet

I am delighted to have been awarded a project to study the genomics and epigenomics of immune innovations in insects, as part of the DFG-funded SPP “Genomic Basis of Evolutionary Innovations (GEvol)” (http://www.g-evol.com). The goal of the DFG funded Priority Programme GEvol is to collaboratively and interdisciplinarily exploit new computational and OMICS methods to reveal the history of genomes in the insect taxon by comparative genomics.

For my project ImmuNov, I am recruiting a PhD student to study the evolution of innate immunity in insects. The project involves comparative analysis of the gene expression response (i.e. transcriptomics) of several insect species against generalist pathogens, and of the epigenetic regulation of immunity. The focus will be on genetic novelty and understanding how and how often new genes emerged and acquired an immune function in the evolutionary history of insects.

If you are interested in applying, please get in contact with me, and apply online here (deadline is 25th September 2022): https://stellenangebote.uni-ulm.de/jobposting/c99925141fbf4bd57b3c15fe67d4e01dae78b1b7

Check out our new publication!

vincentdoublet

In this new work, we investigated the effect of different diets on several fitness traits in bumble bee workers. Using Bombus terrestris, we manipulated the amino acid to carbohydrate (AA:C) ratio they consumed, as well as the amino acid blend.

We found that AA:C ratio did not significantly affect survival following food removal or ovarian activation. However, high amino acids intake increased body mass, which is positively correlated with multiple fitness traits in bumble bees.

We also found an interaction between amino acids blend and dietary AA:C ratio affecting survival during feeding experiments, and signs that there may have been weak, interactive effects on food consumption.

When I say we, of course, I meant our fantastic bachelor students, that did all the work. I was happy to be involved in that project in supervising their progress in the lab.

That was a fun project lead by Ruth! Check it our here.

Our new paper is out!

vincentdoublet

As a relatively recent concept, the OneHealth approach is the collaborative effort of medical, veterinary and environmental sciences for the improvement of human, animal and ecosystems health.

Within this context, we believe that bees, as essential pollinators of our crop plants as well as wild flowers, represent an important group for the maintenance of our health, and that of our habitats. In this review, we expose why, through direct and indirect effects, plant pollination by bees is so important for the well-being of our societies and ecosystems, as well as for the production of high-quality food for everyone.

We also discuss why bees, with their diversity in social behavior and ecological niche, represent interesting models for wildlife epidemiology. In fact, the recent growing concern about bee diseases taught us a lot about the effect of host community composition and structure on disease emergence, the role of social structure in disease dynamics, and the importance of food quality and diversity for mounting an efficient immune response.

With this paper, our goal is to present bee health in a wider context of ecosystem health. I hope you will enjoy our review, published within a special issue on OneHealth in the Journal of Invertebrate Pathology.

The reference:

Wilfert L, Brown MJF, Doublet V. (2020) OneHealth implications of infectious diseases of wild and managed bees. Journal of Invertebrate Pathology, in press. doi: 10.1016/j.jip.2020.107506

Edit (7.12.2020): a free access to the paper until January 25th 2020 at: https://authors.elsevier.com/c/1cByX534PuwGh