Publications by authors named "Nicolas Chartier"

This article presents data on farming operations traceability and associated performances, for winegrowing systems with low phytosanitary inputs. 343 farms were sampled from the DEPHY network: a governmental initiative to produce references on phytosanitary-efficient cropping systems under real conditions of production. Data were collected every campaign between 2017 and 2020, by multiple extensionists who provide support to the voluntarily enlisted growers, in exchange for traceability of their practices and their commitment to reducing pesticide use.

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Oocytes are large cells that develop into an embryo upon fertilization. As interconnected germ cells mature into oocytes, some of them grow-typically at the expense of others that undergo cell death. We present evidence that in the nematode , this cell-fate decision is mechanical and related to tissue hydraulics.

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Article Synopsis
  • Cells usually finish division with cytokinesis, but some tissues can end up with connected cells, forming a syncytium, which occurs in various species including humans.
  • The study focused on the germline of Caenorhabditis elegans to explore how syncytia develop and maintain, revealing that their formation depends on two specific actomyosin proteins.
  • The findings suggest that syncytial tissues can withstand mechanical stress due to their elastic properties, which could be a common trait for similar tissues across different organisms.
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Cytokinesis generally produces two separate daughter cells, but in some tissues daughter nuclei remain connected to a shared cytoplasm, or syncytium, through incomplete cytokinesis. How syncytia form remains poorly understood. We studied syncytial formation in the Caenorhabditis elegans germline, in which germ cells connect to a shared cytoplasm core (the rachis) via intercellular bridges.

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Regulation of cell cycle duration is critical during development, yet the underlying molecular mechanisms are still poorly understood. The two-cell stage Caenorhabditis elegans embryo divides asynchronously and thus provides a powerful context in which to study regulation of cell cycle timing during development. Using genetic analysis and high-resolution imaging, we found that deoxyribonucleic acid (DNA) replication is asymmetrically regulated in the two-cell stage embryo and that the PAR-4 and PAR-1 polarity proteins dampen DNA replication dynamics specifically in the posterior blastomere, independently of regulators previously implicated in the control of cell cycle timing.

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The four related mammalian MEX-3 RNA-binding proteins are evolutionarily conserved molecules for which the in vivo functions have not yet been fully characterized. Here, we report that male mice deficient for the gene encoding Mex3b are subfertile. Seminiferous tubules of Mex3b-deficient mice are obstructed as a consequence of the disrupted phagocytic capacity of somatic Sertoli cells.

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RNA-binding proteins of the evolutionarily-conserved MEX-3 family are mediators of post-transcriptional regulation in different organisms. Recent studies highlight their involvement in diverse physiological settings, including the maintenance of a balance between stem cell self-renewal and differentiation. Here, we draw attention to their putative role in tissue homeostasis and disease, particularly cancer.

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The homeobox transcription factor CDX2 plays a crucial role in intestinal cell fate specification, both during normal development and in tumorigenic processes involving intestinal reprogramming. The CDX2 regulatory network is intricate, but it has not yet been fully uncovered. Through genome-wide screening of a 3D culture system, the RNA-binding protein MEX3A was identified as putatively involved in CDX2 regulation; therefore, its biological relevance was addressed by setting up cell-based assays together with expression studies in murine intestine.

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Integrity of the epithelial barrier is determined by apical junctional complexes which also participate in the signalling pathways inducing intestinal cell differentiation. Lipid rafts (LR) have been proposed to play a role in the organization and the function of these intercellular complexes. This study investigated potential mechanisms by which LR could participate in the establishment of adherens junctions (AJ) and the initiation of enterocytic differentiation.

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Background: The serine/threonine kinase LKB1 regulates cell growth and polarity in metazoans, and loss of LKB1 function is implicated in the development of some epithelial cancers. Despite its fundamental role, the mechanism by which LKB1 regulates polarity establishment and/or maintenance is unclear. In the present study, we use the nematode C.

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Asymmetric cell division is the process by which a single cell gives rise to two different daughter cells. This process is important to generate cell diversity during the development of multicellular organisms, as well as for stem cell self-renewal in adults. Current knowledge on so-called cancer stem cells suggests that a loss of asymmetry during their division could lead to overproliferation and favour tumorigenesis, highlighting the importance of deciphering the mechanisms governing asymmetric cell division.

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Asymmetric cell division is an important process to generate cell diversity and maintain tissue homeostasis. Recent evidence suggests that this process may also be crucial to prevent tumor formation. In the past 30 years, the embryo of the nematode Caenorhabditis elegans has proven to be a very powerful model to study the molecular and cellular basis of asymmetric cell division.

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Depending on its cellular localization, p120 catenin (p120ctn) can participate in various processes, such as cadherin-dependent cell-cell adhesion, actin cytoskeleton remodeling, and intracellular trafficking. Recent studies also indicate that p120ctn could regulate cell proliferation and contact inhibition. This report describes a new function of p120ctn in the regulation of cell cycle progression.

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Human intestinal cell differentiation is mediated by signaling pathways that remain largely undefined. We and others have shown that cell migration and differentiation along the crypt-villus axis is associated with temporal and spatial modulations of the repertoire, as well as with the function of integrins and E-cadherins and their substrates. Cross-talk between integrin and cadherin signaling was previously described and seems to coordinate this differentiation process.

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