Insect vertebrate-like circadian clock is sensitive to weak magnetic fields. Even in darkness.
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| Year of publication | 2023 |
| Type | Conference abstract |
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| Citation | |
| Description | The circadian clock is an endogenous mechanism whose disruption (e.g. by exposure to unnatural light) results in a multitude of health problems. Steady magnetic fields (SMF) of unnatural intensity and radiofrequency (RF) electromagnetic smog accompanying modern man belong to potential disruptors. The aim of this study was to test the hypothesis that unnatural SMF and RF alters insect circadian rhythm. For this study we chose lindenbug Pyrrhocoris apterus. This heteropteran insect has the same clock protein Cryptochrome II (CRYII) as vertebrates. Besides, CRY is likely candidate for the animal magnetoreceptor. We monitored locomotor activity over 10 days under constant conditions in the absence of light. Three types of SMF (0 µT, 50 µT, 120 µT) and three types of broadband RF (40 pT, 415 pT, 2300 pT) were applied. The motion of each individual placed in petri dish was detected by image analysis SW. The actograms were analysed by Image J SW. Periods were compared between groups using one-way ANOVA or Kruskal-Wallis test. We found that under SMF 120 µT, the rhythm was accelerated (KW, n=72, P=0.0002) compared with individuals in SMF with intensity 50 µT and 0 µT. Rhythm acceleration was also caused by RF 415 pT (ANOVA, N=92, P<0.0001). Overall, the work shows that insect circadian rhythm was sensitive to both relatively weak SMFs (only 2.5 times stronger than natural) and to RFs even 1000 times weaker. Near zero SMF had no effect and, surprisingly, there was no effect of the strongest RF. Also surprisingly, magnetic sensitivity was light-independent. Since P. apterus uses the same molecular clock mechanism as vertebrates and light is not essential for magnetic sensitivity, our results may also be relevant for understanding the sensitivity of human cells to electromagnetic smog and magnetically unnatural conditions in the environment of modern man. The work was supported by the Ministry of Agriculture of the Czech Republic grant QK1910286. |
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