Figure 2: PINK1 and Parkin are required for the mitochondrial maintenance in Drosophila melanogaster. (a) Wings are kept in a horizontal position in wild-type fly (upper) while PINK1 knockdown in the muscles results in a drooped wing posture (arrowhead) due to the degeneration of the flight muscle mitochondria (lower). Data were adapted from [43]. (b) Transmission electron microscopy (TEM) analysis of the indirect flight muscle and morphology of mitochondria in 2-day-old adult flies. PINK1- and Parkin-deficient flies showed elongated and swollen mitochondria with indistinct cristae. Some mitochondria are outlined with broken lines to highlight morphology. Overhead view of wild-type (normal), PINK1- and Parkin-deficient flies is also shown. Scale bars = 1 μm in upper panels and 200 nm in lower. Original data were published in [27].