The TOR and Insulin/IGF signalling (IIS) network controls growth, metabolism and ageing. Although reducing TOR or insulin signalling can be beneficial for ageing, it can be detrimental for wound healing, but the reasons for this difference are unknown. Here we show that IIS is activated in the cells surrounding an epidermal wound in Drosophila melanogaster larvae, resulting in PI3K activation and redistribution of the transcription factor FOXO. Insulin and TOR signalling are independently necessary for normal wound healing, with FOXO and S6K as their respective effectors. IIS is specifically required in cells surrounding the wound, and the effect is independent of glycogen metabolism. Insulin signalling is needed for the efficient assembly of an actomyosin cable around the wound, and constitutively active myosin II regulatory light chain suppresses the effects of reduced IIS. These findings may have implications for the role of insulin signalling and FOXO activation in diabetic wound healing.
Cell–cell adhesion and cell shape are regulated at adherens junctions during embryonic morphogenesis. Beati et al. show that the Drosophila LIM domain protein Smallish interacts with Bazooka, Canoe, and Src42A at adherens junctions. Loss-of-function and gain-of-function phenotypes reveal a function for Smallish in regulation of actomyosin contractility and cell shape.
The Drosophila larva has been used to investigate many processes in cell biology, including morphogenesis, physiology, responses to drugs and new therapeutic compounds. Despite its enormous potential as a model system, it has technical limitations in cases where longer-term live imaging is necessary, because of the lack of efficient methods for immobilising larvae for extended periods. We describe here a simple procedure for anaesthetisation and long-term in vivo imaging of the epidermis and other larval organs including gut, imaginal discs, neurons, fat body, tracheae and haemocytes, and show a procedure for probing cell properties by laser ablation. We include a survey of different anaesthetics, showing that short exposure to diethyl ether is the most effective for long-term immobilisation of larvae. This method does not require specific expertise beyond basic Drosophila genetics and husbandry, and confocal microscopy. It enables high-resolution studies of many systemic and subcellular processes in larvae.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.