Autophagy is an intracellular degradation pathway in which cytoplasmic components are directed to the degradative organelle, the lysosome (red) where the constituents are broken down. This membrane-mediated process proceeds in distinct steps. The cytoplasmic constituents are enclosed by the double membrane structure called the Isolation membrane/phagophore. The resultant autophagosome in turn fuses with the lysosome forming the autolysosome where the enclosed material is broken down. We have established transgenic flies carrying fusion proteins to the autophagy markers Atg5 (blue) and Atg8 (green) (Rusten T.E et al. 2004). Upon autophagic stimulation, autophagsosomes (green) end up in lysosomes (red) appearing as yellow in the resultant autolysosomes.
The transgenic fly stocks that were used in the study; Programmed autophagy in the Drosophila fat body is induced by ecdysone through regulation of the PI3K pathway(Rusten T.E., et al. 2004) have been deposited at the Bloomington Stock Centre. The stock numbers are;
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Contact information: Department of Molecular Cell Biology, Institute for Cancer Research The Norwegian Radium Hospital, Montebello, N-0379 Oslo, Norway Telephone +47 22 78 18 18 (Stenmark), +47 22 78 12 70 (Dept. Secretary) Email: h.a.stenmark@medisin.uio.no