63 research outputs found

    PS Integrins and Laminins: Key Regulators of Cell Migration during Drosophila Embryogenesis

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    During embryonic development, there are numerous cases where organ or tissue formation depends upon the migration of primordial cells. In the Drosophila embryo, the visceral mesoderm (vm) acts as a substrate for the migration of several cell populations of epithelial origin, including the endoderm, the trachea and the salivary glands. These migratory processes require both integrins and laminins. The current model is that αPS1βPS (PS1) and/or αPS3βPS (PS3) integrins are required in migrating cells, whereas αPS2βPS (PS2) integrin is required in the vm, where it performs an as yet unidentified function. Here, we show that PS1 integrins are also required for the migration over the vm of cells of mesodermal origin, the caudal visceral mesoderm (CVM). These results support a model in which PS1 might have evolved to acquire the migratory function of integrins, irrespective of the origin of the tissue. This integrin function is highly specific and its specificity resides mainly in the extracellular domain. In addition, we have identified the Laminin α1,2 trimer, as the key extracellular matrix (ECM) component regulating CVM migration. Furthermore, we show that, as it is the case in vertebrates, integrins, and specifically PS2, contributes to CVM movement by participating in the correct assembly of the ECM that serves as tracks for migration

    Lack of an Antibacterial Response Defect in Drosophila Toll-9 Mutant

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    Toll and Toll-like receptors represent families of receptors involved in mediating innate immunity response in insects and mammals. Although Drosophila proteome contains multiple Toll paralogs, Toll-1 is, so far, the only receptor to which an immune role has been attributed. In contrast, every single mammalian TLR is a key membrane receptor upstream of the vertebrate immune signaling cascades. The prevailing view is that TLR-mediated immunity is ancient. Structural analysis reveals that Drosophila Toll-9 is the most closely related to vertebrate TLRs and utilizes similar signaling components as Toll-1. This suggests that Toll-9 could be an ancestor of TLR-like receptors and could have immune function. Consistently, it has been reported that over-expression of Toll-9 in immune tissues is sufficient to induce the expression of some antimicrobial peptides in flies. These results have led to the idea that Toll-9 could be a constitutively active receptor that maintain significant levels of antimicrobial molecules and therefore provide constant basal protection against micro-organisms. To test theses hypotheses, we generated and analyzed phenotypes associated with a complete loss-of-function allele of Toll-9. Our results suggest that Toll-9 is neither required to maintain a basal anti-microbial response nor to mount an efficient immune response to bacterial infection

    RNA-sequencing elucidates the regulation of behavioural transitions associated with mating in honey bee queens

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    This study was funded by a BBSRC ISIS grant BB/J019453/1, a Royal Holloway Research Strategy Fund Grant, and a Leverhulme Grant F/07537/AK to MJFB. BPO was supported by Australian Research Council Discovery grants DP150100151 and DP120101915. FM was supported by a Marie Curie International Incoming Fellowship FP7-PEOPLE-2013-IIF-625487 to MJFB. We would like to thank Dave Galbraight (Penn State) and Alberto Paccanaro (RHUL) for support with analysis of RNAseq data and four anonymous reviewers for providing thoughtful insights that helped to improve the manuscript.Peer reviewedPublisher PD

    Comparison of historical violins by non-destructive MRI depth profiling

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    The back plates of master violins at the Ashmolean Museum in Oxford and the Museo del Violino in Cremona were analyzed by portable magnetic resonance imaging with the NMR-MOUSE in terms of depth profiles. Distributions of transverse NMR relaxation times were recorded versus depth at points of small curvature across the violin back plates providing insight into the physical states of the materials. Their analysis reveals the effects of surface treatments, wood treatment, and possible wood degradation. While conclusions about the type of treatment cannot be drawn, the profiles report surprising differences between the violins from the museums in Oxford and Cremona

    Comparison of historical violins by non-destructive MRI depth profiling

    No full text
    The back plates of master violins at the Ashmolean Museum in Oxford and the Museo del Violino in Cremona were analyzed by portable magnetic resonance imaging with the NMR-MOUSE in terms of depth profiles. Distributions of transverse NMR relaxation times were recorded versus depth at points of small curvature across the violin back plates providing insight into the physical states of the materials. Their analysis reveals the effects of surface treatments, wood treatment, and possible wood degradation. While conclusions about the type of treatment cannot be drawn, the profiles report surprising differences between the violins from the museums in Oxford and Cremona
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