Résumé

Author summary Phlebotomine sand flies are small insects, mostly known for their role in the transmission of Leishmania parasites to humans and other mammals. In French Guiana, the main clinical form of the disease manifests as cutaneous lesions also called American cutaneous leishmaniasis. The transmission of Leishmania from wild mammals to humans depends on the species of sand fly involved in the transmission. To better understand the mechanism of disease transmission, it is essential to accurately identify sand flies, including both vector and non-vector species. Until now, sand flies have mainly been identified using morphological and molecular methods. Recent studies have shown that a new tool based on protein profiling compiled in a library of spectra may be useful for the identification of arthropod vectors. This tool has the advantage of being less time-consuming, less expensive and does not require technical skills. The aim of this study was to assess the usefulness and accuracy of this new tool in identifying Northern Amazonian sand flies.


Auteurs, date et publication :

Auteurs Agathe Chavy , Cécile Nabet , Anne Cécile Normand , Arthur Kocher , Marine Ginouves , Ghislaine Prévot , Thiago Vasconcelos dos Santos , Magalie Demar , Renaud Piarroux , Benoît de Thoisy

Publication : PLOS Neglected Tropical Diseases

Date : 2025

Volume : 13

Issue : 2

Pages : e0007031


Catégorie(s)

#CNRS #FORET Nouragues

Auteurs, date et publication :

Auteurs Sophie Fauset , Michelle O Johnson , Manuel Gloor , Timothy R Baker , Abel Monteagudo , Roel JW Brienen , Ted R Feldpausch , Gabriela Lopez-Gonzalez , Yadvinder Malhi , Hans Ter Steege

Publication : Nature Communications

Date : 2025

Volume : 6

Pages : 6857


Catégorie(s)

#CNRS #FORET Nouragues

Auteurs, date et publication :

Auteurs Eric Kuhnert , Simone Heitkämper , Jacques Fournier , Frank Surup , Marc Stadler

Publication : Fungal biology

Date : 2025

Volume : 118

Issue : 2

Pages : 242-252


Catégorie(s)

#CNRS #FORET Nouragues

Auteurs, date et publication :

Auteurs Jérémy Lemaire , Olivier Marquis , Paco Bustamante , Rosanna Mangione , François Brischoux

Publication : Environmental Research

Date : 2023

Volume : 194

Pages : 110494


Catégorie(s)

#CNRS #FORET Nouragues

Auteurs, date et publication :

Auteurs Charlotte Kounda-Kiki , Jean-François Ponge , Philippe Mora , Corinne Sarthou

Publication : Pedobiologia

Date : 2025

Volume : 52

Issue : 2

Pages : 85-95


Catégorie(s)

#CNRS #FORET Nouragues

Résumé

Stem water storage capacity and hydraulic capacitance (CS) play a crucial role in tree survival under drought-stress. To investigate whether CS adjusts to increasing water deficit, variation in stem water content (StWC) was monitored in vivo for 2 years and related to periodical measurements of tree water potential in Mediterranean Quercus ilex trees subjected either to permanent throughfall exclusion (TE) or to control conditions. Seasonal reductions in StWC were larger in TE trees relative to control ones, resulting in greater seasonal CS (154 and 80 kg m−3 MPa−1, respectively), but only during the first phase of the desorption curve, when predawn water potential was above −1.1 MPa. Below this point, CS decreased substantially and did not differ between treatments (<20 kg m−3 MPa−1). The allometric relationship between tree diameter and sapwood area, measured via electrical resistivity tomography, was not affected by TE. Our results suggest that (a) CS response to water deficit in the drought-tolerant Q. ilex might be more important to optimize carbon gain during well-hydrated periods than to prevent drought-induced embolism formation during severe drought stress, and (b) enhanced CS during early summer does not result from proportional increases in sapwood volume, but mostly from increased elastic water.


Auteurs, date et publication :

Auteurs Roberto L. Salomón , Kathy Steppe , Jean M. Ourcival , Selwyn Villers , Jesús Rodríguez‐Calcerrada , Roderick Schapman , Jean M. Limousin

Publication : Plant, Cell & Environment

Date : 2025

Volume : 43

Issue : 6

Pages : 1528-1544


Catégorie(s)

#CNRS #FORET Puechabon

Résumé

Adipose tissue is an organ with metabolic, endocrine and immune functions. In this tissue, the expressions of genes associated with several metabolic pathways, including lipid metabolism, have been shown to be affected by genetic selection for feed efficiency, an important trait to consider in livestock. We hypothesized that the stimulation of immune system caused by poor hygiene conditions of housing impacts the molecular and cellular features of adipose tissue and that the impact may differ between pigs that diverge in feed efficiency. At the age of 12 weeks, Large White pigs from two genetic lines divergent for residual feed intake (RFI) were housed in two contrasting hygiene conditions (good vs poor). After six weeks of exposure, pigs were slaughtered (n = 36). Samples of blood, subcutaneous (SCAT) and perirenal (PRAT) adipose tissues were collected for cell response and gene expression investigations. The decrease in the relative weight of PRAT was associated with a decline in mRNA levels of FASN, ME, LCN2 and TLR4 (P < 0.05) in pigs housed in poor conditions compared with pigs housed in good conditions for both RFI lines. In SCAT, the expressions of only two key genes (PPARG and TLR4) were significantly affected by the hygiene of housing conditions. Besides, the mRNA levels of both LCN2 and GPX3 were influenced by the RFI line (P 0.05). We also investigated the expressions of genes involved in the immune response and lipid metabolism in whole blood cells cultured in the absence and presence of LPS. The hygiene conditions had no effect but, the relative expression of the GPX3 gene was higher (P < 0.001) in high RFI than in low RFI pigs while the expressions of IL-10 (P = 0.027), TGFβ1 (P = 0.023) and ADIPOR2 (P = 0.05) genes were lower in high RFI than in low RFI pigs. Overall, the current study indicates that the hygiene of housing had similar effects on both RFI lines on the expression of genes in adipose tissues and on the features of SCAT adipose cells and whole blood cells in response to TNF-α and LPS. It further demonstrates that the number of genes with expression impacted by housing conditions was higher in PRAT than in SCAT. It suggests a depot-specific response of adipose tissue to the current challenge.


Auteurs, date et publication :

Auteurs Audrey Quéméner , Marie-Hélène Perruchot , Frédéric Dessauge , Annie Vincent , Elodie Merlot , Nathalie Le Floch , Isabelle Louveau

Publication : PeerJ

Date : 2022

Volume : 10

Pages : e14405


Catégorie(s)

#CNRS #EcoGenO #Université de Rennes

Auteurs, date et publication :

Auteurs Sandra Lavorel , Karl Grigulis

Publication : Journal of Ecology

Date : 2025

Volume : 100

Issue : 1

Pages : 128-140


Catégorie(s)

#CNRS #Lautaret #UGA

Auteurs, date et publication :

Auteurs Sébastien Ibanez , Fabien Arène , Sébastien Lavergne

Publication : Oecologia

Date : 2025

Volume : 180

Issue : 4

Pages : 989-1000


Catégorie(s)

#CNRS #Lautaret #UGA

Résumé

Abstract. The partitioning of photosynthates toward biomass compartments plays a crucial role in the carbon (C) sink function of forests. Few studies have examined how carbon is allocated toward plant compartments in drought-prone forests. We analyzed the fate of gross primary production (GPP) in relation to yearly water deficit in an old evergreen Mediterranean Quercus ilex coppice severely affected by water limitations. Carbon fluxes between the ecosystem and the atmosphere were measured with an eddy covariance flux tower running continuously since 2001. Discrete measurements of litterfall, stem growth and fAPAR allowed us to derive annual productions of leaves, wood, flowers and acorns, and an isometric relationship between stem and belowground biomass has been used to estimate perennial belowground growth. By combining eddy covariance fluxes with annual net primary productions (NPP), we managed to close a C budget and derive values of autotrophic, heterotrophic respirations and carbon-use efficiency (CUE; the ratio between NPP and GPP). Average values of yearly net ecosystem production (NEP), GPP and Reco were 282, 1259 and 977 g C m−2. The corresponding aboveground net primary production (ANPP) components were 142.5, 26.4 and 69.6 g C m−2 for leaves, reproductive effort (flowers and fruits) and stems, respectively. NEP, GPP and Reco were affected by annual water deficit. Partitioning to the different plant compartments was also impacted by drought, with a hierarchy of responses going from the most affected – the stem growth – to the least affected – the leaf production. The average CUE was 0.40, which is well in the range for Mediterranean-type forest ecosystems. CUE tended to decrease less drastically in response to drought than GPP and NPP did, probably due to drought acclimation of autotrophic respiration. Overall, our results provide a baseline for modeling the inter-annual variations of carbon fluxes and allocation in this widespread Mediterranean ecosystem, and they highlight the value of maintaining continuous experimental measurements over the long term.


Auteurs, date et publication :

Auteurs S. Rambal , M. Lempereur , J. M. Limousin , N. K. Martin-StPaul , J. M. Ourcival , J. Rodríguez-Calcerrada

Publication : Biogeosciences

Date : 2014

Volume : 11

Issue : 23

Pages : 6855-6869


Catégorie(s)

#CNRS #FORET Puechabon