Mitonuclear interactions affect locomotor activity and sleep in Drosophila melanogaster

Abstract

Mitochondria are organelles that produce cellular energy in the form of ATP through oxidative phosphorylation, and this primary function is conserved between many taxa. Locomotion is a trait that is highly reliant on metabolic function and expected to be greatly affected by disruptions to mitochondrial performance. To this end, we aimed to examine how activity and sleep vary between Drosophila melanogaster strains with different geographic origins, how these patterns are affected by mitochondrial DNA (mtDNA) variation, and how breaking up co-evolved mito-nuclear gene combinations affect the studied activity traits. The results demonstrate that Drosophila strains from different locations differ in sleep and activity, and the extent of variation differs between sexes, females in general being more active. By comparing activity and sleep of mtDNA variants introgressed onto a common nuclear background in cytoplasmic hybrid (cybrid) strains, we establish that mtDNA variation affects both traits, sex specifically. Furthermore, by using previously published mtDNA copy number data, we detected a positive correlation between mtDNA copy number and the activity levels of the cybrid flies. Altogether, our study shows that both mtDNA variation and mitonuclear interactions affect activity and sleep patterns, highlighting the important role that both genomes play on life-history trait evolution.

IMD-mediated innate immune priming increases Drosophila survival and reduces pathogen transmission

“…We then processed the raw activity data using the DAM System File Scan Software (Pfeiffenberger et al, 2010). We analysed fly activity data using three metrics (Anderson et al, 2022; V. Gupta et al, 2017; Siva-Jothy and Vale, 2019; Vale and Jardine, 2015): total activity, the average activity during 5-min activity bouts, and proportion of 5-min bouts with zero activity (which has been defined as sleep in Drosophila (Shaw et al, 2000)) ( Fig. S2-III)…”

“…We then processed the raw activity data using the DAM System File Scan Software [53]. We analysed fly activity data using three metrics [45,[54][55][56]: total activity, the average activity during 5-min activity bouts, and proportion of 5-min bouts with zero activity (which has been defined as sleep in Drosophila [57]) (Fig. S2-III)…”

Effects of reactive oxygen species and mitochondrial dysfunction on reproductive aging

“…Asymmetric inheritance of mtDNA presents a novel perspective for explaining the sex difference in lifespan expectancy: the accumulation of mtDNA mutations may potentially make an adverse consequence for males if they are neutral or advantageous for females (Innocenti et al, 2011). These effects may manifest directly, such as through mitochondrial function (Anderson et al, 2022), or indirectly, such as retroegulation of nuclear genome by mtDNA (Hamalainen et al, 2019). However, the substantial variations in the reproductive cycle and the pace of reproductive senescence among males and females have yet to be adequately elucidated and warrant further investigation.…”

IMD-mediated innate immune priming increases Drosophila survival and reduces pathogen transmission

“…We then processed the raw activity data using the DAM System File Scan Software [75]. We analysed fly activity data using three metrics [76][77][78][79]: total activity, the average activity during 5-min activity bouts, and proportion of 5-min bouts with zero activity (which has been defined as sleep in Drosophila [80]) (S2III Fig)…”