Comptes Rendus Biologies最新文献

The increase in knowledge in the life sciences in recent decades has given rise to developments that are likely to offer unprecedented opportunities for improving the living conditions of man and his environment. Knowledge and know-how in biology and biotechnology and their access facilitated by the generalization of information systems accessible to the greatest number of people are disrupting many behaviors and ways of thinking. This raises ethical and societal questions that relate in particular to the appropriateness of risk assessment in the conduct of certain research due to either the "misuse" that could result from it, or because of a possible major impact on public health or the environment. Among these risks, the proliferation of biological weapons or bioterrorism represents biosecurity and biosafety issues that are today a real current concern. The same applies to the possible consequences of incidents or accidents that may occur during the handling of pathogenic microorganisms or particularly dangerous viruses. In the early 2000s, Professor Henri Korn, within the framework of a working group of the French Academy of Sciences, has undertaken to deepen these questions and to take an interest in raising the awareness of scientists of what is known under the generic term dual use research concern (DURC). He was managing a working group on this topic and published a report in 2008, entitled "Biological threats, biosafety and the responsibility of scientists on research". In 2015, taking into account this report, the government authorities have established by decree a National Advisory Council for Biosafety (CNCB), and have entrusted its coordination jointly to the General Secretariat for Defense and National Security (SGDSN) and the French Academy of Sciences. Since 2015, the CNCB has been asked to consider several issues, including a report on dual use research of concern, published in 2019. More recently, the CNCB has focused on biological laboratory incidents and accidents. These reports were the subject of recommendations, in particular concerning initial and continuing training in "the assessment of the risks of duality in research" and the support of legitimate dual use research.

Soil management practices are of particular importance, as they are the basis of 60% of planetary ecosystem services. Positive environmental externalities are associated with methods inspired by agroecology, whereas conventional methods generally have elevated indirect environmental costs. Public policies that take this reality into account are needed to make agriculture a solution rather than an obstacle to the regeneration of the planetary environment. Soil-based ecosystem services, the support for primary production, climate control through carbon sequestration, hydrological services and the biodiversity associated to their delivery, are usually associated in "bundles of ecosystem services". We propose to use communities of soil macroinvertebrates, the ones visible at the naked eye, as estimators of all other services to which they are strongly correlated. Macroinvertebrates are represented by a great diversity of biological forms, and indicator species for soil functions have been identified in several studies by scientists. The 15 orders commonly found in most soils are known to soil managers. Estimating their communities is easy and inexpensive with the widely used standard ISO/TSBF method. A numerical indicator constructed from data collected in several thousand sites sampled by this method is proposed, which can be applied everywhere. It allows to calculate for any site a value that has been shown to be a reliable proxy for the global chemical, physical and biological functions that these invertebrates stimulate in the soil, in mutualistic associations with other soil organisms. In conclusion, we discuss the feasibility of a generalized use of this indicator by farmer communities as a support for public policies that will organize the fair recognition and remuneration of positive externalities generated by some practices.

At a time when biological research is booming, driven by the explosion in synthetic biology and sequencing capabilities, as well as the phenomenal biological data these fields generate, debates are raging among experts and in society at large.The major pandemic crisis triggered by SARS-CoV-2 has resurrected debates about laboratory safety and our ability to respond to biological risks. Current geopolitical instability is also prompting us to take a closer look at the threats posed by the potential use of biological weapons.Therefore, the question of the acceptable risk of biological research arises, which must take into consideration, on the one hand, the importance of research for our health, environment and quality of life, and, on the other hand, our ability to take into account safety, security and dual-use issues. The aim of this review is to take stock of the risks identified and the measures taken in France to limit them.

Despite having a miniature brain-smaller than one cubic millimeter and comprising roughly one million neurons-honey bees display a rich behavioral repertoire in which learning and memory play a central role. This raises the question of whether their adaptive behavior extends beyond simple forms of learning, and whether the neural mechanisms underlying complex cognition can be elucidated in this insect model. Elemental olfactory conditioning, where bees learn to associate an odorant with a sucrose reward, has provided an unparalleled framework to dissect the neural circuits underlying conditioned (odor) and unconditioned (sucrose) stimulus processing. This work revealed how these pathways converge in the brain-particularly within the antennal lobes, lateral horn, and mushroom bodies-and how learning reshapes neural coding, notably at the level of the antennal lobe. Beyond elemental tasks, bees master non-elemental discriminations such as negative patterning and biconditional learning, which require configural processing. Neural interference studies identify the mushroom bodies as essential for these higher-order functions. Even more complex capacities have been demonstrated: bees categorize visual stimuli, learn abstract rules (sameness, difference, above/below), transfer learning across sensory modalities, and display numerical competence, including rudimentary arithmetic and an understanding of zero. Together, these findings reveal a degree of cognitive sophistication once thought unique to vertebrates and establish the honey bee as a powerful system for investigating both basic and advanced cognitive processes, as well as their neural foundations, within a miniature brain.

The ongoing environmental crisis, driven by human activities, has resulted in significant biodiversity losses across various taxa, affecting ecosystem functioning. To deal with this crisis, policymakers have notably established the Kunming-Montreal Global Biodiversity Framework, which includes targets to mitigate biodiversity loss by 2050. To achieve this goal, reliable and ecologically relevant indicators are essential to quantify and qualify biodiversity changes. Temporal trends in species abundance or occurrence have been proposed as useful indicators. In France, the Vigie-Nature program engages volunteers in biodiversity monitoring through various schemes, thereby producing relevant data to estimate country-wide temporal trends for various taxonomic groups. Some indicators of population trends are already produced for some taxa, but the analysis pipelines remain unpublished and need extensions to accommodate monitoring schemes collecting presence/absence instead of abundance data, such as the Vigie-flore plant monitoring scheme. Here, we present a newly developed analysis pipeline to estimate population trends, which handles different data types and protocol specificities, and goes beyond linear population trends by considering multiple time periods and visualizing non-linear dynamics. In addition to introducing the methodology and making it available, we ran this pipeline to produce population trends for 148 bird and 181 plant species in France, based on abundance data from STOC (French Breeding Bird Survey) and occurrence data from Vigie-flore schemes. Results show as many increasing as decreasing bird population trends over the past 23 years, and a tendency for more decreasing than increasing plant population trends over the past 15 years, thereby revealing significant changes in community composition. Specifically, for birds, most habitat generalist species showed stable or increasing population trends, while most habitat specialist species showed stable or decreasing population trends, suggesting biotic homogenization. This pipeline and first analyses provide an unprecedented overview of bird and plant population trends, and contribute to the production of biodiversity indicators based on open science and reproducible research.

Ribosomes of highly evolved organisms are larger than their bacterial counterparts not only in terms of the number of proteins but also in terms of RNA length extensions. Some extensions do not fold into the three-dimensional structure of the ribosome in cryo-EM analysis and cannot be crystallized for X-ray examination. These expansion segments are not visible due to flexibility. In this mini-review, we propose an approach to study the chick embryo ribosome as an example of a highly evolved organism to visualize the expansion segments and study the mechanism of in situ tetramerization and crystallization of ribosomes.

CRISPR homing gene drive is a disruptive biotechnology developed over the past decade with potential applications in public health, agriculture, and conservation biology. This technology relies on an autonomous selfish genetic element able to spread in natural populations through the release of gene drive individuals. However, it has not yet been deployed in the wild. In this review, we examine the key risks associated with CRISPR homing gene drives. First, we explore technical limitations, where gene drives might not be as efficient as intended, and cases where mitigation strategies may not be able to block a gene drive. Then, we present four main categories of adverse effects: (a) ecological risks, corresponding to unintended consequences on ecosystems and non-target populations; (b) sociological risks, i.e. concerns over public perception, governance, and societal acceptance; (c) risks associated with research activities; and (d) risks associated with malevolent usage. Regulatory aspects are not addressed here. This article provides a foundation for evaluating gene drive risks to ensure responsible and informed decision-making.

The exact details of the emergence of SARS-CoV-2, the virus causing Covid-19, remain unknown. Scientific publications using data available to date point to a natural origin linked to the wildlife trade at a market in Wuhan, China. Yet, theories postulating a research-related origin of SARS-CoV-2 abound, and currently dominate the public discussion of the origin of the Covid-19 pandemic. Here, we attempt to characterize the diversity of research-related origin scenarios, discuss their characteristics and evidence base, or the lack thereof, and highlight mutual incompatibilities between some scenarios. We then focus on a feature of SARS-CoV-2 that is central in today's leading research-related hypotheses, namely the insertion that led to the introduction of a polybasic cleavage site in the spike glycoprotein. We examine various scenarios put forward to explain this insertion in a research-related context, and we show how SARS-CoV-2's evolution in humans has provided examples demonstrating that such insertions happen naturally.

Forest fungi are crucial for the function and sustainability of forest ecosystems. This article reviews the current understanding of the biology and ecology of two main fungal guilds in forests: saprotrophic fungi, which decompose plant detritus and soil organic matter, and symbiotic mycorrhizal fungi, which promote tree growth. I will explore the factors influencing the diversity and dynamics of fungal communities in forest soils under climate change conditions. Finally, I briefly discuss research programs aimed at defining the conditions for utilising tree microbiota, particularly mycorrhizal symbionts, in planting and assisted migration projects for forestry species. Controlled mycorrhiza formation allows for the production of young forest seedlings mycorrhized with selected fungal strains, thereby enhancing the mineral and water nutrition of seedlings, stimulating juvenile growth, and increasing resistance to drought and pathogens. It is also used for truffle cultivation and edible mushroom production.

Organoids and embryoids are self-organizing 3D cellular models derived from human pluripotent stem cells or dissociated stem cells from primary tissue, able of partially mimicking the development and function of tissues, organs, or embryos in vitro. Research using these models is advancing rapidly, starting to overcome challenges in studying human development, evolution, and disease. The conference from the French Académie des Sciences "Mini-organs and early embryos in vitro: what is at stake?" illustrated the promise of organoids and embryoids in basic and translational research. The lectures emphasized recent biomedical applications, particularly in disease modeling, drug discovery, and regenerative medicine. Current challenges and future directions have also been discussed alongside with the ethical implications of generating functional structures from human cells in vitro.