...Nikolas Nikolaou; Tomomi Watanabe-Asaka; Sebastian Gerety; Martin Distel; Reinhard W. Köster; David G. Wilkinson Previous studies have identified roles of the modulation of Notch activation by Fringe homologues in boundary formation and in regulating the differentiation of vertebrate thymocytes...

... , the close association of the longitudinal glia (LG) with the neuropil provides an excellent opportunity to identify and characterize neuron-glial signals in vivo. We have found that the activity and restricted expression of the glycosyltransferase Fringe (Fng)renders a subset of LG sensitive to activation...

... morphology, but,as noted above, the edges of these clones are sometimes irregular. Importantly, Delta-expressing clones, which are generally rounder than Fringe-expressing clones, are often associated with an upregulation of F-actin and a smooth interface at the adherens junctions (15/25 dorsal clones...

...Liang Lei; Aiguo Xu; Vladislav M. Panin; Kenneth D. Irvine Two glycosyltransferases that transfer sugars to EGF domains, OFUT1 and Fringe, regulate Notch signaling. However, sites of O -fucosylation on Notch that influence Notch activation have not been previously identified. Moreover...

... of the full-length but not an activated form of Notch. Further, we show that neurotic is required for Fringe activity, which encodes a fucose-specific β1, 3 N -acetylglucosaminyltransferase, previously shown to modulate Notch receptor activity. Finally, Neurotic is essential for the physical interaction...

... not require extension by Fringe to confer the phenotype. Our results suggest functional differences between Notch in neural and non-neural cells. R8 precursor cells are protected from lateral inhibition by Delta. The protection is affected by modifications of a particular EGF repeat in the Notch extracellular...

... segregation of D and V cell populations by at least two distinct mechanisms. The LRR transmembrane proteins Capricious and Tartan are transiently expressed in D cells and contribute to initial segregation of D and V cells. Signaling between D and V cells mediated by Notch and Fringe contributes...

... by the activation of Notch. We have investigated their role in follicle patterning by creating clones of cells mutant for the Notch modulator fringe . This genetic ablation of polar cells results in cell fate defects within surrounding follicle cells. At the anterior, the border cells, the immediately adjacent...

... for dorsal follicle cell patterning has no influence on pipe expression. Clonal analysis shows that also the mirror - fringe cassette suggested to establish a secondary signalling centre in the follicular epithelium is not involved in pipe regulation. These findings support the view that the pipe domain...

... and thus segmentation must be coordinated with tissue growth. I demonstrate that segmentation of the Drosophila leg, as assayed by expression of the key regulators of segmentation, the Notch ligands and fringe , occurs progressively and I define the sequence in which the initial segmental subdivisions...

...Muriel Grammont; Kenneth D. Irvine fringe encodes a glycosyltransferase that modulates the ability of the Notch receptor to be activated by its ligands. We describe studies of fringe function during early stages of Drosophila oogenesis. Animals mutant for hypomorphic alleles of fringe contain...

... of the ap mutant phenotype with genes known to be downstream of Ap. We show that Fringe (Fng), a secreted protein involved in modulation of Notch signaling, is sufficient to rescue D/V compartmentalization, margin formation and wing outgrowth when appropriately expressed in an ap mutant background. When Fng...

... development by its target gene dLMO . Apterous-dependent expression of Serrate and fringe in dorsal cells leads to the restricted activation of Notch along the dorsoventral compartment boundary. We present evidence that the ability of cells to participate in this Apterous-dependent cell-interaction is under...

... genes, such as wingless and cut , are expressed in a 2-to 4-cell-wide domain. The interactions between Notch and its ligands are modulated by Fringe via a mechanism that may involve post-transcriptional modifications of Notch. The ligands themselves also help to restrict Notch activity...

... of the eye disc. This boundary region seems to be established by the genes of the iroquois complex, which are expressed in the dorsal half of the disc and inhibit fringe expression there. Fringe controls the activation of Notch and the expression of its ligands, with the result that Notch is activated only...

... between Delta and Notch can affect the ability of a cell to generate and to transduce a Delta-mediated signal. Finally, we present evidence that the Fringe protein can interfere with Delta- and Serrate-mediated signalling within developing bristle organs, in contrast to previous reports of the converse...

..., which regulates the expression of the Notch ligand, Serrate, and the Fringe signalling molecule. The other Notch ligand, Delta, also plays a role in the development and patterning of the wing. It has been proposed that Fringe modulates the ability of Serrate and Delta to signal through Notch and thereby...

... due to the action of the fringe gene product. Using ectopic expression, we show that regulation of Serrate by fringe occurs at the level of protein and not Serrate transcription. Furthermore, replacement of the N-terminal region of Serrate with the corresponding region of Delta abolishes the ability...

...Stuart H. Johnston; Cordelia Rauskolb; Richa Wilson; Bindu Prabhakaran; Kenneth D. Irvine; Thomas F. Vogt ABSTRACT The formation of boundaries between groups of cells is a universal feature of metazoan development. Drosophila fringe modulates the activation of the Notch signal trans-duction pathway...