Search results for " morphogenesis"
showing 10 items of 30 documents
Evolution of Leaf Morphogenesis: Evidence from Developmental and Phylogenetic Data in Papaveraceae
1999
Variation of leaf morphology in Papaveraceae s.l. (including Fumariaceae and Pteridophyllum) has previously been shown to be related to developmental differences in the direction of segmentation and in blade‐petiole differentiation. Based on ontogenetic comparisons, we here distinguish polyternate, acropetal, basipetal‐pedate, basipetal‐pinnate, and divergent modes of dissection. In addition, undissected leaves occur in some taxa. Dissection modes can be grouped in two classes on the basis of blade‐petiole differentiation. Mapping of these morphogenetic traits on an independently obtained phylogenetic reconstruction reveals a high degree of homoplasy, indicating multiple evolutionary parall…
Planar Cell Polarity Signaling in Collective Cell Movements During Morphogenesis and Disease
2012
Collective and directed cell movements are crucial for diverse developmental processes in the animal kingdom, but they are also involved in wound repair and disease. During these processes groups of cells are oriented within the tissue plane, which is referred to as planar cell polarity (PCP). This requires a tight regulation that is in part conducted by the PCP pathway. Although this pathway was initially characterized in flies, subsequent studies in vertebrates revealed a set of conserved core factors but also effector molecules and signal modulators, which build the fundamental PCP machinery. The PCP pathway in Drosophila regulates several developmental processes involving collective cel…
Synthesis of tumor-associated glycopeptide antigens.
2002
Carbohydrates and peptides linked together in glycoproteins constitute important components of the molecular communication between cells in multicellular organisms. Cell morphogenesis and tumorigenesis are accompanied by changes in the glycoprotein profiles of the outer cell membranes. Glycopeptide fragments of glycoproteins that have altered structures in tumor cells are of interest as tumor-associated antigens for the distinction between normal cells and tumor cells. In contrast to glycoproteins isolated from biological sources, synthetic glycopeptides are obtained in pure form and exactly specified structures. The methods developed for the synthesis of glycopeptides with tumor-associated…
MEK1 Required for Invasive Growth of mIMCD3 renal Cells in a 3D Collagen Matrix
2004
Branching morphogenesis is an essential process during kidney development: This process controls epithelialization of the metanephric mesenchyme during the induction of branching structures and in this way determines the number of nephrons. Various grow factors, such HGF, have been implicated in branching morphogenesis in renal cells, including mIMCD3 ( murine inner medullary collecting duct) and MDCK cells. Growth factors which induce branching morphogenesis in renal cells also activate the MEK1/ERK pathway. The authors analyzed the potential role that this pathway might play in branching morphogenesis. The authors show that PD98059, a specific inhibitor of MEK1,inhibits branching of mIMCD…
Hjelmslev et la "fonction sémiotique", du modèle structural au modèle cognitif
2008
The article discusses the concept of semiotics function in Hjelmslev, finding sources of the theory of language’s stratification. The semiotic function, which is in Hjelmslev the principle underlying the dynamic layering, is identified here as both an attraction of two heterogeneous spaces and as a set of operations of sense’s establishment. At historiographic level, this article presents a new hypothesis of interpretation, that the hjelmslevian structuralism has not built a static theory of language, disinterested to the cognitive dimension, but a careful theory to operational aspects of semiosis.
Tenectin is a novel alphaPS2betaPS integrin ligand required for wing morphogenesis and male genital looping in Drosophila.
2010
International audience; Morphogenesis of the adult structures of holometabolous insects is regulated by ecdysteroids and juvenile hormones and involves cell-cell interactions mediated in part by the cell surface integrin receptors and their extracellular matrix (ECM) ligands. These adhesion molecules and their regulation by hormones are not well characterized. We describe the gene structure of a newly described ECM molecule, tenectin, and demonstrate that it is a hormonally regulated ECM protein required for proper morphogenesis of the adult wing and male genitalia. Tenectin's function as a new ligand of the PS2 integrins is demonstrated by both genetic interactions in the fly and by cell s…
Mandibular-pelvic-patellar syndrome (mpp) is a novel pitx1-related disorder due to alteration of pitx1 transactivation ability
2020
International audience; PITX1 is a homeobox transcription factor essential for hindlimb morphogenesis. Two PITX1-related human disorders have been reported to date: PITX1 ectopic expression causes Liebenberg syndrome, characterized by malformation of upper limbs showing a "lower limb" appearance; PITX1 deletions or missense variation cause a syndromic picture including clubfoot, tibial hemimelia, and preaxial polydactyly. We report two novel PITX1 missense variants, altering PITX1 transactivation ability, in three individuals from two unrelated families showing a distinct recognizable autosomal dominant syndrome, including first branchial arch, pelvic, patellar, and male genital abnormaliti…
Supervised exercise training in peripheral arterial disease increases vascular shear stress and profunda femoral artery diameter
2016
Background Arteriogenesis is promoted by flow- and pressure-related forces such as tangential wall stress and laminar shear stress. Exercise training (ET) is known to promote arteriogenesis in peripheral arterial disease (PAD) patients. It remains unclear whether supervised ET (SET) promotes arteriogenesis more efficiently than non-SET (nSET). Methods and results Forty PAD patients participated in a SET or nSET training programme ( n = 20 each) and were compared to 20 healthy individuals without any history of cardiovascular events. Femoral artery diameter, flow and velocity were measured by ultrasound. Tangential wall stress and laminar shear stress were calculated for femoral arteries. Fo…
Gyrification from constrained cortical expansion
2014
The exterior of the mammalian brain - the cerebral cortex - has a conserved layered structure whose thickness varies little across species. However, selection pressures over evolutionary time scales have led to cortices that have a large surface area to volume ratio in some organisms, with the result that the brain is strongly convoluted into sulci and gyri. Here we show that the gyrification can arise as a nonlinear consequence of a simple mechanical instability driven by tangential expansion of the gray matter constrained by the white matter. A physical mimic of the process using a layered swelling gel captures the essence of the mechanism, and numerical simulations of the brain treated a…
The 5' Untranslated Region of the
2018
Many of the virulence traits that make Candida albicans an important human fungal pathogen are regulated on a transcriptional level. Here, we report an important regulatory contribution of translation, which is exerted by the extensive 5′ untranslated regulatory sequence (5′ UTR) of the transcript for the protein Efg1, which determines growth, metabolism, and filamentation in the fungus. The presence of the 5′ UTR is required for efficient translation of Efg1, to promote filamentation. Because transcripts for many relevant regulators contain extensive 5′ UTR sequences, it appears that the virulence of C. albicans depends on the combination of transcriptional and translational regulatory mec…