G9a regulates group 2 innate lymphoid cell development by repressing the group 3 innate lymphoid cell program.

Innate lymphoid cells (ILCs) are emerging as important regulators of homeostatic and disease-associated immune processes. Despite recent advances in defining the molecular pathways that control development and function of ILCs, the epigenetic mechanisms that regulate ILC biology are unknown. Here, we identify a role for the lysine methyltransferase G9a in regulating ILC2 development and function. Mice with a hematopoietic cell-specific deletion of G9a (Vav.G9a(-/-) mice) have a severe reduction in ILC2s in peripheral sites, associated with impaired development of immature ILC2s in the bone marrow. Accordingly, Vav.G9a(-/-) mice are resistant to the development of allergic lung inflammation. G9a-dependent dimethylation of histone 3 lysine 9 (H3K9me2) is a repressive histone mark that is associated with gene silencing. Genome-wide expression analysis demonstrated that the absence of G9a led to increased expression of ILC3-associated genes in developing ILC2 populations. Further, we found high levels of G9a-dependent H3K9me2 at ILC3-specific genetic loci, demonstrating that G9a-mediated repression of ILC3-associated genes is critical for the optimal development of ILC2s. Together, these results provide the first identification of an epigenetic regulatory mechanism in ILC development and function

Pollen tube energetics: respiration, fermentation and the race to the ovule

This review covers historical and recent progress in understanding how respiration, fermentation and mitochondria contribute to pollen tube growth. It also summarizes what is known about the energetic requirements of this growth. Molecular mechanisms are viewed in the context of pollen tube physiology, a necessary perspective to understanding pollen tube growth

Acquisition and Evolution of Plant Pathogenesis–Associated Gene Clusters and Candidate Determinants of Tissue-Specificity in Xanthomonas

is a large genus of plant-associated and plant-pathogenic bacteria. Collectively, members cause diseases on over 392 plant species. Individually, they exhibit marked host- and tissue-specificity. The determinants of this specificity are unknown. lineage. genome and indicate that differentiation with respect to host- and tissue-specificity involved not major modifications or wholesale exchange of clusters, but subtle changes in a small number of genes or in non-coding sequences, and/or differences outside the clusters, potentially among regulatory targets or secretory substrates

Le voyage de la Terre Sainte composé par Maitre Denis Possot et achevé par Messire Charles Philippe

Preface: Schefer, Ch.]Dedication:Content description: IndexIllustration: (Maps ,Views ,)Pagination: PP16+352PVolumes: 1Text Genre:ProseIllustration: (χάρτες ,τοπία ,

Etude du gene glnA de Methanococcus voltae et construction d'un vecteur d'integration permettant d'exprimer un marqueur de resistance eubacterien chez cette archaebacterie methanogene

SIGLEINIST T 74130 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Les pélerins de Jérusalem en Champagne au XVIe siècle

Appartient à l’ensemble documentaire : ChArdenn

Coumarin and quinolone action in archaebacteria: evidence for the presence of a DNA gyrase-like enzyme.

The action of novobiocin and coumermycin (two coumarins which interact with the gyrB subunit of eubacterial DNA gyrase) and ciprofloxacin (a fluoroquinolone which interacts with the gyrA subunit of DNA gyrase) was tested on several archaebacteria, including five methanogens, two halobacteria, and a thermoacidophile. Most strains were sensitive to doses of coumarins (0.02 to 10 micrograms/ml) which specifically inhibit DNA gyrase in eubacteria. Ciprofloxacin inhibited growth of the haloalkaliphilic strain Natronobacterium gregoryi and of the methanogen Methanosarcina barkeri. In addition, ciprofloxacin partly relieved the sensitivity to coumarins (and vice versa). Novobiocin inhibited DNA replication in Halobacterium halobium rapidly and specifically. Topological analysis has shown that the 1.7-kilobase plasmid from Halobacterium sp. strain GRB is negatively supercoiled; this plasmid was relaxed after novobiocin treatment. These results support the existence in archaebacteria of a coumarin and quinolone target related to eubacterial DNA gyrase