The mineral and isotopic composition, and the 3D spatial distribution of asteroid constituents are key parameters to understand the physico-chemical processes operating in the protoplanetary disk and/or in the asteroidal parent bodies all along Solar System history. The sample return missions Hayabusa2/JAXA and OSIRIS-REx/NASA targeted two small and dark near-Earth objects: C-type Ryugu and B-type Bennu (R&B). The main goal of this project is to significantly advance the knowledge and understanding of the origin and evolution of R&B and their primary parent bodies, by studying their returned samples in the laboratory. This will be achieved by combining: i/ some of the most advanced in-situ analytical techniques on selected R&B materials, to reveal their structure and their mineral and isotopic composition; ii/ a multi-scale approach that links the nm-µm lab measurements to remote asteroid observations; iii/ analyses/experiments on meteorites, IDPs and analogs to support the interpretation of R&B data. A multi-analytical sequence will be used, from less destructive (e.g., spectroscopy) to more destructive (e.g., NanoSIMS or TEM) techniques, with the main goal of maximizing the scientific outcomes and minimizing sample loss. The consortium brings together scientists from four French laboratories (IAS, UMET, IMPMC, IPAG) with different backgrounds (astro- and cosmo-chemists, astrophysicists, astronomers, geologists, physicists). They have already participated in the study of samples from Stardust (NASA) and Hayabusa (JAXA), are now part of four Hayabusa2 preliminary examination teams, and have past experience of fruitful collaboration. Our analyzes will elucidate the formation of R&B, their protoplanetary heritage, and post-accretion evolution, in particular aqueous and surface alteration. They will contribute to the more general effort to understand the origin and evolution of matter in planetary systems.

The aim of the FRiPPon project is to explore an emerging class of fungal peptides, called dikaritins, and to understand their role as chemical effectors in fungi interacting with plants. Fungi produce a wide range of secondary metabolites (SMs) acting as chemical effectors to colonize their ecological niche. In particular, phytopathogenic and endophytic species produce SMs to manipulate the physiology of their host or its microbiote. The recently discovered dikaritins are considered as the main class of ribosomally synthesized and post-translationally modified peptides (RiPPs) in Ascomycetes. The first identified dikaritins attracted attention because they are phytotoxins (Ustiloxins, Phomopsins) or effectors manipulating plant immunity (Victorin). Based on the specific features of the biosynthesis of the five dikaritins identified so far i.e. the need for a precursor protein named KEP (Kexin-Processed Protein) and at least one DUF3328 (Domain of unknown function 3328) enzyme for cyclisation, genome mining studies revealed hundreds of dikaritin biosynthetic gene clusters (BGCs) in fungi, in plant pathogenic species but also in beneficial endophytes. In addition, preliminary transcriptomic analyses indicate that some of the dikaritin BGCs are activated in the presence of the host plants which suggests that they play a specific role in these biotic interactions. The specific objectives of the FRiPPon project are: (i) To discover new bioactive dikaritins from fungi interacting with plants, (ii) to explore their chemical diversity, (iii) to characterize their bioactivities in plants and microorganisms, and (iv) to evaluate their potential in agronomic applications. To reach these objectives, the program will focus on a set of four fungal species with well-characterized interactions with plants and high-quality genomic and transcriptomic data: Botrytis cinerea, a polyphagous necrotrophic plant pathogen, Colletotrichum higginsianum, a plant pathogen with contrasting biotrophic and necrotrophic stages on Arabidopsis thaliana, C. tofieldiae, a beneficial root endophyte of A. thaliana and Leptosphaeria maculans a plant pathogen that shows biotrophic, endophytic and necrotrophic stages of infection on rapeseed. Importantly, the project also includes three Penicillium strains that are beneficial for plant growth and show strong agronomic interest for the industrial partner (CMI Roullier). The main challenge of the project is to isolate dikaritins that are weakly (or not) produced in the absence of the plant. To overcome this technical bottleneck, we will carefully identify the BGCs of interest and express them in a heterologous host i.e. yeast. Then, state-of-the-art techniques will be used to extract and purify the dikaritins and to determine their chemical structures. We anticipate obtaining at least five new bioactive dikaritins that will be further tested on plants and microorganisms. In parallel, fungal genetics studies will be conducted to evaluate the role of these chemical effectors in plant-fungal interactions. FRiPPon is a PRCE that draws together two academic institutes, the BIOGER institute (INRAE) and the MNHN, with expertise in fungal-plant interactions and chemical ecology, respectively, and the CMI – Roullier company that develops natural products for the agronomic industry. On an academic level, this interdisciplinary project is expected to help to decipher how fungi manipulate plant hosts or antagonize competitors in their ecological niche, and to reveal new dikaritin chemical structures. Finally, the exploration of this untapped source of fungal SMs will pave the way for the development of sustainable and natural solutions for use in agronomy.

Extant holocephalans are an anatomically bizarre group of deep sea dwelling fishes which are highly adapted to durophagy, and extraordinarily slow-evolving. They are also the tip of a lineage which has survived three big mass-extinctions. Thus, holocephalans have great potential as a case study in how evolution shapes morphology in response to selection pressures over vast periods of time, and how this morphology is affected by mass extinction events. We will bring together new collaborations to investigate the relationship between the form of the holocephalan skull and jaws and their function in durophagy. We will take a novel approach based around three objectives: functional morphology, ontogeny, and paleontology. The methods we will use have never been applied to this question before. We expect this project to lay the groundwork for future collaboration between our teams, as well as helping to develop the application of similar modelling methods to other fields of paleontology.

Since the industrial revolution, the level of physical activity drastically declined while the amount of ingested calories increased and those of essential omega-3 fatty acids (w3) decreased. Physical activity, caloric intake and w3 are beneficial for health and survival. However, no study tried to identify the interactions between these parameters, and given their importance, we hypothesize that a strong synergistic effect may exist between them. We thus propose to test the effects of a multi-modal intervention combining chronic caloric restriction (CR), physical activity (ACT) and optimal w3 levels on longevity and brain ageing in a primate (Microcebus murinus). The three interventions will be applied either individually (ACT, CR, w3) or in interaction (ACT/CR/w3, ACT/w3, ACT/CR, CR/w3). The project will focus on age-related neurodegeneration in link with cognitive functions and metabolic disorders. For the first time in mouse lemur, we will use non-invasive methods to evaluate biomarkers of central nervous system alterations, based on retina study, through the emerging concept of “the eye as a window to the brain”. A lower rate of age-related pathologies and extended lifespan are expected in the group receiving the three treatments. This synergistic approach represents new avenues to an optimal longevity.

A better understanding of past climate variations and their interactions with geosphere and biosphere is essential to understand future climatic changes. Most of the available paleoenvironmental proxies were developed for and applied to oceanic environments. However, it is essential to develop new proxies applicable to continental environments to assess climatic variability over the continents and improve our understanding of past global environmental changes. Membrane lipids produced by certain microorganisms can be used to achieve this goal. Microorganisms are able to adjust their membrane composition in response to the prevailing environmental conditions to ensure the optimal state of the cellular membrane. Analysis of bacterially-produced branched GDGTs (brGDGTs) in soils, peats and lakes distributed worldwide showed that their chemical structure varies mainly with air temperature and to a lesser extent soil pH, making them increasingly used as paleoproxies since more than fifteen years. BrGDGTs are the only microbial organic proxies available for temperature reconstructions in both aquatic and terrestrial settings. Nevertheless, corresponding paleoenvironmental data have to be interpreted with care, as these compounds may have allochthonous and autochthonous sources in aquatic settings and brGDGT source microorganisms remain unknown. The development of environmental proxies independent and complementary to brGDGTs is crucial to improve the reliability and accuracy of continental paleoreconstructions. The ambition of the ALPINE project is to propose a new environmental proxy applicable to lake environments, based on 3-hydroxy fatty acids (3-OH FAs), membrane lipids produced by Gram-negative bacteria. These organic compounds were recognized as potential temperature and pH proxies after their analysis in a large set of soils distributed worldwide. Nevertheless, the influence of environmental parameters on 3-OH FA distribution in lacustrine environments and the applicability of 3-OH FAs as temperature and pH proxies in such settings has not been investigated in detail yet, despite the high sensitivity of lacustrine archives as recorders of past environmental conditions. It is now essential to obtain accurate information on the adaptation of 3-OH FA source microorganisms to temperature/pH changes in lakes before potentially developing robust and universal (paleo)environmental proxies applicable to both aquatic and terrestrial settings. The main objectives of this project will be (i) to investigate the applicability of 3-OH FAs as new temperature and pH proxies in lakes and (ii) to concomitantly constrain the limits and conditions of use of existing GDGT-based proxies in such settings. To this aim, the source(s) of microbial lipids in lakes will first be assessed. Then, the effect of temperature and pH on lacustrine microorganisms and their membrane lipids will be investigated by combining field and laboratory experiments – lake sediment microcosm incubations with 13C- and 2H-labeled substrates and isolation cultures. The degradability of 3-OH FAs in lacustrine sediments under biotic and abiotic conditions will be concomitantly examined. We then envision to develop calibrations between temperature/pH and distribution of microbial lipids in sediments from lacustrine sediments collected worldwide. Last, these calibrations will be applied to long-term paleoenvironmental reconstructions from lacustrine cores. This interdisciplinary project represents a unique opportunity to gather together researchers with complementary expertise for the development of an environmental tool. It will be based on an integrated approach coupling state-of-the-art organic geochemistry molecular biology, electron microscopy, and isotope techniques, applied to samples from present and past times.