# Hypomagnetic Fields Influence the Developmental Duration, Fecundity and Temperature Stress Resistance of Drosophila melanogaster via Frataxin-Associated Traits

## TL;DR

This study shows that low magnetic fields affect the development, reproduction, and stress resistance of fruit flies with a genetic deficiency in a key mitochondrial protein.

## Contribution

The study is the first to show how hypomagnetic fields affect frataxin-deficient fruit flies across multiple biological traits.

## Key findings

- Hypomagnetic fields extended developmental duration in frataxin-deficient fruit flies.
- Exposure increased fecundity and improved heat shock recovery in these flies.
- HMF had no significant effect on adult weight but enhanced stress resistance.

## Abstract

As a highly conserved and important mitochondrial protein, frataxin plays a key role in iron homeostasis and metabolism, and its deficiency is associated with the Friedreich’s ataxia phenotype, a cardio- and neurodegenerative disease in humans. A hypomagnetic field can lead to various biological effects including increased oxidative stress, abnormal neurological functions, and developmental disorders; yet, its effects as an environmental stressor that exacerbates the inherent metabolic vulnerabilities in organisms, e.g., frataxin-deficient fruit flies, is still unknown. Thus, we used a hypomagnetic field to investigate its biological effects on frataxin-deficient fruit flies, and found that hypomagnetic field exposure could extend developmental duration, increase the fecundity of fruit flies, and accelerate recovery from heat shock in frataxin-deficient flies. Our findings indicate that the hypomagnetic field is adverse for growth and development but in favor of reproduction and temperature stress resistance to some extent in frataxin-deficient fruit flies. This study provides the first evidence of the multidimensional effects of hypomagnetic fields on frataxin-deficient fruit flies and offers inspiration and reference for space hypomagnetic effect exploration and Friedreich’s ataxia therapy.

Frataxin is a highly conserved mitochondrial protein that plays a key role in iron homeostasis and metabolism, and its deficiency leads to oxidative stress, mitochondrial dysfunction, and neurodegeneration. Hypomagnetic fields (HMF) can lead to various biological effects including increased oxidative stress, neurological and developmental disorders; yet, their effects acting as environmental stressors that exacerbate the inherent metabolic vulnerabilities in frataxin-deficient Drosophila melanogaster flies are still unknown. In this study, the bio-effects of HMF on growth, development, reproduction, and temperature stress resistance of frataxin-silenced flies were investigated. The results showed that HMF extended egg-to-adult and pupa developmental durations of both the control line of repo-GAL4; tub-GAL80^ts>GFP-RNAi (GFP-RNAi) and frataxin-deficient line of repo-GAL4; tub-GAL80^ts>fh RNAi (fh-RNAi) compared to those reared under a geomagnetic field (GMF). Compared with GMF, HMF significantly increased offspring fecundity in fh-RNAi flies, whereas the change in GFP-RNAi controls was not significant, while showing no significant effects on the adult weight of fh-RNAi flies. The impact of HMF on temperature stress resistance was particularly specific: it enhanced recovery from chill coma in control (GFP-RNAi) flies, while it accelerated recovery from heat shock in frataxin-silenced (fh-RNAi) flies. The mechanisms through which HMF modulate frataxin-associated phenotypes at a fundamental physical level warrant further investigation.