Les invasions biologiques

International audienceCet « article » est la transcription - par Christine Silvy - d'une émission radiophonique de France Culture, La Science et les hommes (Atelier du savoir), préparée et animée par Françoise Breton (désignée par FB). Lancés sur les ondes le 2 avril 1997, les propos des cinq invités et de la productrice sont reportés ici sans réarrangement ni réécriture de fond. Un débat livré en différé (dont les arguments n'ont pas vieilli) auquel on a voulu conserver sa spontanéité et son langage parlé

Contribution of NFP LysM Domains to the Recognition of Nod Factors during the Medicago truncatula/Sinorhizobium meliloti Symbiosis

The root nodule nitrogen fixing symbiosis between legume plants and soil bacteria called rhizobia is of great agronomical and ecological interest since it provides the plant with fixed atmospheric nitrogen. The establishment of this symbiosis is mediated by the recognition by the host plant of lipo-chitooligosaccharides called Nod Factors (NFs), produced by the rhizobia. This recognition is highly specific, as precise NF structures are required depending on the host plant. Here, we study the importance of different LysM domains of a LysM-Receptor Like Kinase (LysM-RLK) from Medicago truncatula called Nod factor perception (NFP) in the recognition of different substitutions of NFs produced by its symbiont Sinorhizobium meliloti. These substitutions are a sulphate group at the reducing end, which is essential for host specificity, and a specific acyl chain at the non-reducing end, that is critical for the infection process. The NFP extracellular domain (ECD) contains 3 LysM domains that are predicted to bind NFs. By swapping the whole ECD or individual LysM domains of NFP for those of its orthologous gene from pea, SYM10 (a legume plant that interacts with another strain of rhizobium producing NFs with different substitutions), we showed that NFP is not directly responsible for specific recognition of the sulphate substitution of S. meliloti NFs, but probably interacts with the acyl substitution. Moreover, we have demonstrated the importance of the NFP LysM2 domain for rhizobial infection and we have pinpointed the importance of a single leucine residue of LysM2 in that step of the symbiosis. Together, our data put into new perspective the recognition of NFs in the different steps of symbiosis in M. truncatula, emphasising the probable existence of a missing component for early NF recognition and reinforcing the important role of NFP for NF recognition during rhizobial infection

Antonine Maillet : Interview

Collin Françoise, Maillet Antonine. Antonine Maillet : Interview. In: Les Cahiers du GRIF, n°12, 1976. Parlez-vous française ? Femmes et langages I. pp. 44-48

Thérapies assistées par les dauphins pour des enfants souffrant d'un handicap (comparaison de trois méthodes)

LYON1-BU Santé (693882101) / SudocTOULOUSE-EN Vétérinaire (315552301) / SudocNANTES-Ecole Nat.Vétérinaire (441092302) / SudocSudocFranceF

DSCG 1 : gestion juridique, fiscale et sociale : manuel : 2020-2021

National audienc

The [URE3] Yeast Prion Results from Protein Aggregates That Differ from Amyloid Filaments Formed in Vitro

International audienceThe [URE3] yeast prion is a self-propagating inactive form of the Ure2 protein. Ure2p is composed of two domains, residues 1-93, the prion-forming domain, and the remaining C-terminal part of the protein, which forms the functional domain involved in nitrogen catab-olite repression. In vitro, Ure2p forms amyloid filaments that have been proposed to be the aggregated prion form found in vivo. Here we showed that the biochemical characteristics of these two species differ. Protease digestions of Ure2p filaments and soluble Ure2p are comparable when analyzed by Coomassie staining as by Western blot. However, this finding does not explain the pattern specifically observed in [URE3] strains. Anti-bodies raised against the C-terminal part of Ure2p revealed the existence of proteolysis sites efficiently cleaved when [URE3], but not wild-type crude extracts, were submitted to limited proteolysis. The same anti-bodies lead to an equivalent digestion pattern when recombinant Ure2p (either soluble or amyloid) was analyzed in the same way. These results strongly suggest that aggregated Ure2p in [URE3] yeast cells is different from the amyloid filaments generated in vitro

Gestion juridique, fiscale et sociale. Manuel. DSCG1 (diplôme supérieur de comptabilité et de gestion, UE 1)

National audienc

Comment la fouille de données peut renouveler la démarche de construction des indicateurs agro-environnementaux ? Exemple de l'indicateur Icarab

International audienc

DSCG 1 : gestion juridique, fiscale et sociale : manuel

International audienc

Gestion juridique, fiscale et sociale. Manuel. DSCG1 (diplôme supérieur de comptabilité et de gestion, UE 1)

International audienc