Catégorie d'actualités: significant publications

Biodiversity skepticism?

Biodiversity skepticism?

Based on analysis of time series of abundances of insect species in the United States, Crossley et al. reported in Nature Ecology & Evolution (August 2020) that there is no evidence of a global decline in insect abundance or diversity in the United States, this for both natural and anthropogenic sites. Their study described the apparent robustness of insect populations in the U.S. as reassuring, in contrast to recent studies reporting dramatic declines in their abundance around the world.

However, a multidisciplinary consortium including researchers from INRAE, the University of Rennes and CNRS identified major problems in the Crossley et al. paper concerning: 1) statistical analysis and 2) inconsistencies in data selection. The consortium demonstrates, in a commentary published in Nature Ecology & Evolution Desquilbet et al. , that these biases call into question the conclusions of Crossley et al.

This is the second time (see here) that a high-ranking publication downplaying insect declines has been subject to methodological criticisms. These studies raise the question of a "biodiversity-skepticism" within the scientific community. In order to implement an appropriate protection of biodiversity, public decision-makers need an informed diagnosis that is not clouded by biased studies which slow down decision-making.

Reference :
Desquilbet M, Cornillon PA, Gaume L & Bonmatin JM (2021)
Matters arising: Adequate statistical modelling and data selection are essential when analysing abundance and diversity trends
Nature Ecology & Evolution doi : https://www.nature.com/articles/s41559-021-01427-x

J.-M. Bonmatin co-author of an article in One Health (18 March 2021)

The “One Health” concept links environmental, animal (wild & livestock) and human health. It is increasingly being argued (e.g. Covid-19) and is now essential for the preservation of ecosystems and public health. Researchers from the universities of Leuven (BE), Sorbonne-CNRS-IRD-INRAE-UPEC (FR), CARI (BE), FNOSAD (FR) and the Centre for Molecular Biophysics (CNRS), have applied this concept to the case of biocides and veterinary products (including pesticides) that are used to treat livestock and that impact pollinators. These researchers have shown that these "multi-use substances" present (among other things) proven risks for bees and consequently need to be better assessed before being placed on the market. This work was initiated at the CBM in 2019: see here & here (Italian).

Reference :     Mahefarisoa KL, Simon Delso N, Zaninotto V, Colin ME & Bonmatin JM (2021) The Threat of Veterinary Medicinal Products and Biocides on Pollinators: A One Health Perspective, One Health, https://doi.org/10.1016/j.onehlt.2021.100237

 




Decline in insect populations

A group of multidisciplinary co-authors from INRAE, CNRS and several universities (FR, BE & UK) has just published a scientific article in Science (Desquilbet et al., 2020). In the form of a ‘Technical comment’, this article identifies numerous data errors and methodological biases in a meta-analysis published in Science in April 2020 (Van Klink et al., 2020). As a result, the conclusions of Van Klink et al. on a more nuanced decline in terrestrial insects and on an increase in aquatic insects are invalidated. Our new publication reflects less the contradictory aspects of the research, than the emergence and growth of a "biodiversity scepticism". This biodiversity scepticism* must be apprehended. It minimises the impact of humans on nature (e.g. agriculture and pesticides) and is reminiscent of the climate scepticism that has caused a great deal of time to be lost in climate decision-making. J.-M. Bonmatin and his co-authors call for greater rigour in the conduct of such meta-analyses which are at the basis for stakeholders' decisions on key global issues.

Reference: Desquilbet M., Gaume L., Grippa M., Céréghino R., Humbert J.F., Bonmatin J.M., Cornillon P.A., Maes D., Van Dyck H. & Goulson D. (2020) Comment on “Meta-analysis reveals declines in terrestrial but increases in freshwater insect abundances”, Science, 370 (6523)

*See: The Conversation 2019, Nature 2020, Le Monde 2020 & Libération 2020

It is in the press: Le Monde 18/01/2021, The Conversation 28/01/2021, Le Monde 30/01/2021, Le Monde 04/02/2021 & CNRS-INEE 08/02/2021

 




Towards new imaging markers for in vivo detection of pathologies such as Alzheimer’s or diabetes

The accumulation of aggregates of certain non-soluble peptides in tissues is characteristic of several pathologies, such as Alzheimer's and Parkinson's diseases, or diabetes. The detection of these amyloid deposits by in vivo imaging would be very useful for an early diagnostic and a better understanding of the molecular mechanisms of these diseases. Researchers from the Molecular Biophysics Center (CBM) and the Toulouse Coordination Chemistry Laboratory (LCC), in collaboration with Portuguese and Hungarian scientists, have taken an important step forward in the design of imaging agents that specifically recognize these amyloid deposits. This work is on the cover of Chemistry A European Journal.

Read more on the website of CNRS Chemistry Institute (INC)




Neonicotinoids

A scientific article linking the contamination of soils by neonicotinoid pesticides and their presence in hair of people in the Philippines has just been published by Jean-Marc Bonmatin et al. (2020) in the journal Science of the Total Environment. This article is part of researches carried out on human health by the Task Force on Systemic Pesticides, which brings together more than sixty independent researchers (www.tfsp.info & Facebook TFSP). This article also sheds light on the exposure of populations, particularly in the context of the possible reintroduction of neonicotinoids for sugar beet in France.

This article is highlighted by the CNRS chemistry institute.

Detection of amyloid peptides: biomarkers for Alzheimer’s Disease and Diabetes

Metal chelates targeted to amyloid peptides are widely explored as diagnostic tools or therapeutic agents for amyloidogenic diseases. For example, gadolinium complexes can be used as MRI probes, while radiocomplexes (64Cu, 99mTc, etc) can be exploited for nuclear imaging. Other metal complexes capable of preventing aggregate formation are proposed to derive therapeutic strategies.

All these molecules are amphiphilic, composed of a hydrophilic part (containing the metal) and a hydrophobic one (capable of targeting the amyloid aggregates). This particular structure enables the formation of micelles in solution.

The groups of CBM and LCC (Toulouse) have found that this micellisation property has drastic and unexpected consequences on their ability to recognize amyloid peptides and a high impact on their in vivo biodistribution.

The researchers have developed a novel probe with nanomolar affinity towards Aβ and amylin, biomarkers of Alzheimer’s Disease and Ddiabetes, respectively.

This exceptional affinity for a metal complex is only obtained if the complex is present as “single molecule”. Once in the micellar form, this affinity drops by 1000-fold.

These results have a direct consequence for the design of novel imaging and therapeutic probes for amyloidogenic pathologies.

See the article

RNA Remodeling Proteins, Methods and Protocols

The second edition of the book “RNA Remodeling Proteins, Methods and Protocols” edited by Marc Boudvillain has just been published.

This volume of the “Methods in Molecular Biology” series compiles new methods to study RNA-protein complexes and the mechanisms leading to their structural remodeling. The volume includes 4 chapters written by CBM researchers and ideally complements the first edition published in 2015.