Basal mitophagy is widespread in Drosophila but minimally affected by loss of Pink1 or parkin

Abstract

Parkinsons disease factors, PINK1 and parkin, are strongly implicated in stress-induced mitophagy in vitro, but little is known about their impact on basal mitophagy in vivo. We generated transgenic Drosophila expressing fluorescent mitophagy reporters to evaluate the impact of Pink1/parkin mutations on basal mitophagy under physiological conditions. We find that mitophagy is readily detectable and abundant in many tissues including Parkinsons disease relevant dopaminergic neurons. However, we did not detect mitolysosomes in flight muscle. Surprisingly, in Pink1 or parkin null flies we did not observe any substantial impact on basal mitophagy. As these flies exhibit locomotor defects and dopaminergic neuron loss, our findings raise questions about current assumptions of the pathogenic mechanism associated with the PINK1/Parkin pathway. Our findings provide evidence that Pink1 and parkin are not essential for bulk basal mitophagy in Drosophila. They also emphasize that mechanisms underpinning basal mitophagy remain largely obscure.\n\nSummaryPINK1/parkin are key mediators of stress-induced mitophagy in vitro but their impact on basal mitophagy in vivo is unclear. Novel Drosophila reporters lines reveal abundant mitophagy in many tissues including dopaminergic neurons but is unaffected by loss of PINK1/parkin.