The tissues were placed in fresh 4% paraformaldehyde in PBS for 48 h at room temperature. Fixed tissues were then dehydrated, cleared in Histo-Clear (National Diagnostics), infiltrated and embedded in Paramat (Gurr). Embedded tissues were sectioned at 5 μm using an automatic microtome; and the sections were stained with Harris’ haematoxylin and eosin. Subsequently, sections were dehydrated, cleared in Histo-Clear and mounted in DPX resin

(VWR BDH) under glass coverslips. Finally, slides were observed and photographed using a light microscope with a digital camera attached. Pieces of flight muscle tissue were also collected on the same days and fixed with 4% paraformaldehyde in PBS for 48 h at room temperature. To determine whether amoebae invaded deep tissues, surface layers of the fixed muscles were removed and the deep tissues were sectioned serially (5 μm thickness) as described above. signaling pathway Acknowledgements The authors are grateful to Mary Lightfoot for the GANT61 purchase supply of healthy locusts in large numbers for this study, which could not have been accomplished without her skilful assistance. This work was partially funded by Birkbeck, University of London,

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