Effects of extremely low-frequency electromagnetic field on different developmental stages of Drosophila melanogaster

Abstract

Purpose

The model biological organism Drosophila melanogaster has been utilized to assess the effect of extremely low-frequency electromagnetic field (ELF-EMF) on locomotion, longevity, developmental dynamics, cell viability and oxidative stress.

Materials and method

Developmental stages of Drosophila melanogaster (Oregon R strain) individually exposed to ELF-EMF (75 Hz, 550 µT) for 6 h once for acute exposure. For chronic exposure, complete life cycle of fly, that is, egg to adult fly was exposed to ELF-EMF for 6 h daily. The effect of exposure on their crawling and climbing ability, longevity, development dynamics, cellular damage and oxidative stress (generation of reactive oxygen species (ROS)) was evaluated.

Results

The crawling ability of larvae was significantly (p < .05) reduced on acute (third stage instar larvae) as well as chronic exposure (F0 and F1 larvae). When locomotion of flies was tested using climbing assay, no alteration was observed in their climbing ability under both acute and chronic exposure; however, when their speed of climbing was compared, a significant decrease in speed of F1 flies was observed (p = .0027) on chronic exposure. The survivability of flies was significantly affected under chronic and acute exposure (at third stage instar larvae). In case of acute exposure of the third stage instar larvae, although all the flies were eclosed by the 17th day, there was a significant decline in the number of flies (p = .007) in comparison to control. While in case of chronic exposure apart from low number of flies eclosed in comparison to control, there was delay in eclosion by one day (p = .0004). Using trypan blue assay, the internal gut damage of third stage instar larvae was observed. Under acute exposure condition at third stage instar larvae, 30% larvae has taken up trypan blue, while only 10% larvae from acute exposure at adult stage. On chronic exposure, 50% larvae of the F1 generation have taken up trypan blue. On evaluation of oxidative stress, there is a significant rise in ROS in case of acute exposure at third stage instar larvae (p = .0004), adult fly stage (p = .0004) and chronic exposure (p = .0001).

Conclusion

ELF-EMF has maximum effects on acute exposure of third stage instar larvae and chronic exposure (egg to adult fly stage). These results suggest that electromagnetic radiations, though, have become indispensible part of our lives but they plausibly affect our health.

Graphical Abstract

Keywords:

• ELF-EMF
• developmental dynamics; Drosophila melanogaster
• electromagnetic pollution
• lifespan
• locomotor ability
• reactive oxygen species

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work underlying this paper was funded by Defence Research Development Organization, Project DIP 269.

Notes on contributors

Neha Agrawal

Dr. Neha Agrawal, PhD, Scientist ‘C’ at Department of Neurobiology, Defense Institute of Physiology and Allied Science, Defense Research Development Organization, Delhi, India. The author has worked in designing this work and carried out experiments.

Kalyani Verma

Kalyani Verma, M-Tech, SRF student at Department of Neurobiology, Defense Institute of Physiology and Allied Science, Defense Research Development Organization, Delhi, India. The author has worked in designing of this work and carried out experiments.

Doli Baghel

Doli Baghel, M.Sc., Technician at Department of Neurobiology, Defense Institute of Physiology and Allied Science, Defense Research Development Organization, Delhi, India. The author has assisted in conducting experiments.

Amitabh Chauhan

Amitabh Chauhan, M.Sc., Technical Officer ‘C’ at Department of Neurobiology, Defense Institute of Physiology and Allied Science, Defense Research Development Organization, Delhi, India. The author has contributed in reviewing of the manuscript.

Dipti N. Prasad

Dr. Dipti N. Prasad, PhD, Scientist ‘F’, Departmental Head at Department of Neurobiology, Defense Institute of Physiology and Allied Science, Defense Research Development Organization, Delhi, India. The author has contributed in drafting and reviewing of the manuscript

Sanjeev K. Sharma

Dr. Sanjeev K. Sharma, PhD, Scientist ‘G’, Head of Department at Department of Biomedical and Instrumentation, Defense Institute of Physiology and Allied Science, Defense Research Development Organization, Delhi, India. The author has provided the in-house developed ELF-EMF machine.

Ekta Kohli

Dr. Ekta Kohli, PhD, Scientist ‘F’ at Department of Neurobiology, Defense Institute of Physiology and Allied Science, Defense Research Development Organization, Delhi, India. The author has contributed in conceptualizing the idea, experimental design, execution, analysis, interpretation of results, and writing of the manuscripts.