Planar polarity decisions in the wing of Drosophila involve assembly asymmetric protein complexes containing conserved receptor Frizzled. In this study, we analyse role Van Gogh/strabismus gene formation these and cell polarisation. We find that Strabismus becomes asymmetrically localised to proximal edge cells. absence strabismus activity, planar proteins Dishevelled Prickle are mislocalised cell. show binds directly is able recruit them membranes. Furthermore, demonstrate putative...

Camptothecin is a specific topoisomerase I poison and highly cytotoxic to eukaryotic cells. In the present study, we show, using pulse field gel electrophoresis assay, that camptothecin induces DNA double strand breaks (DSBs) specifically in newly replicated DNA. these replication associated DSBs dose-dependent manner. At levels of drug which are toxic cell, long-lived, still measurable 24 hr after treatment. Both induced cytotoxicity prevented by co-exposure with aphidicolin--a result...

The subcellular three-dimensional distribution of three polycomb-group (PcG) proteins—polycomb, polyhomeotic and posterior sex combs—in fixed whole-mount Drosophila embryos was analyzed by multicolor confocal fluorescence microscopy. All proteins are localized in complex patterns 100 or more loci throughout most the interphase nuclear volume. rather narrow protein intensities vast majority argues against a PcG-mediated sequestration repressed target genes aggregation into subnuclear domains....

BackgroundThe planar polarization of developing tissues is controlled by a conserved set core polarity proteins. In the Drosophila pupal wing, these proteins adopt distinct proximal and distal localizations in apicolateral junctions that act as subcellular cues to control morphological events. The protein Flamingo (Fmi) localizes both cell boundaries known have asymmetric activity, but molecular basis this activity unknown.ResultsWe examine role Fmi controlling localization wing cells. We...

The core planar polarity proteins localize asymmetrically to the adherens junctions of epithelial cells, where they have been hypothesized assemble into intercellular complexes. Here, we show that are preferentially distributed discrete membrane subdomains ("puncta"), form asymmetric contacts between neighboring cells. Using an antibody internalization assay and fluorescence recovery after photobleaching in prepupal pupal wings, investigated turnover two key proteins, Flamingo Frizzled, find...

In Drosophila the Polycomb group genes are required for long-term maintenance of repressed state many developmental regulatory genes. Their gene products thought to function in a common multimeric complex that associates with response elements (PREs) target and regulates higher-order chromatin structure. We show chromodomain is necessary protein-protein interactions within Polycomb-Polyhomeotic complex. addition, Posterior Sex Combs protein coimmunoprecipitates Polyhomeotic, indicating they...

During planar polarity patterning of the Drosophila wing, a "core" group genes has been identified which acts downstream global cues to locally coordinate cell and specify trichome production at distal edges. These encode protein products that assemble into asymmetric apicolateral complexes straddle proximodistal junctional region between adjacent cells. We have carried out detailed genetic analysis experiments, analysing requirements each complex component for patterning. find three...

Polarised tissue elongation during morphogenesis involves cells within epithelial sheets or tubes making and breaking intercellular contacts in an oriented manner. Growing evidence suggests that cell adhesion can be modulated by endocytic trafficking of E-cadherin (E-cad), but how this process polarised individual is poorly understood. The Frizzled (Fz)-dependent core planar polarity pathway a major regulator rearrangements processes such as gastrulation, has also been implicated regulation...

Highlights•Planar polarity proteins form signalosome-like complexes of variable stoichiometry•Flamingo and Frizzled a stoichiometric nucleus within the complex•Asymmetric localization core is robust to changes in complex composition•Core protein stability not dependent on stoichiometrySummaryIn developing epithelia, planar physically interact with each other localize asymmetrically at opposite cell ends, forming intercellular that link neighboring cells. Using quantitative imaging examine...

Four-jointed (fj) is required for proximodistal growth and planar polarity in Drosophila tissues. It encodes a predicted type II transmembrane protein with putative signal peptidase sites its domain, C terminus secreted. Fj has therefore been proposed to act as secreted signalling molecule. We show that graded distribution eye wing imaginal discs, largely localised the Golgi vivo transfected cells. Forms of are constitutively or anchored were assayed function vivo. find cleavage secretion...

The asymmetric localisation of core planar polarity proteins at apicolateral junctions is required to specify cell in the plane epithelia. This distribution proposed require amplification an initial asymmetry by feedback loops. In addition, generation appears regulation protein levels, but importance such and underlying mechanisms unknown. Here we show that ubiquitylation acts through more than one mechanism control levels Drosophila, without this cellular compromised. Levels Dishevelled are...

The core planar polarity proteins are required to specify the orientation of structures that polarised in plane epithelium. In Drosophila melanogaster wing, localise asymmetrically at either proximal or distal cell edges. Asymmetric localisation is thought be biased by long-range cues, causing asymmetric complexes become aligned with tissue axes. Core then participate feedback interactions necessary amplify asymmetry, and order for such operate correctly, levels junctions must tightly...