Magnetoreception Regulates Male Courtship Activity in Drosophila

Abstract

The possible neurological and biophysical effects of magnetic fields on animals is an area of active study. Here, we report that courtship activity of male Drosophila increases in a magnetic field and that this effect is regulated by the blue light-dependent photoreceptor cryptochrome (CRY). Naïve male flies exhibited significantly increased courtship activities when they were exposed to a ≥ 20-Gauss static magnetic field, compared with their behavior in the natural environment (0 Gauss). CRY-deficient flies, cryb and crym, did not show an increased courtship index in a magnetic field. RNAi-mediated knockdown of cry in cry-GAL4-positive neurons disrupted the increased male courtship activity in a magnetic field. Genetically expressing cry under the control of cry-GAL4 in the CRY-deficient flies restored the increase in male courtship index that occurred in a magnetic field. Interestingly, artificially activating cry-GAL4-expressing neurons, which include large ventral lateral neurons and small ventral lateral neurons, via expression of thermosensitive cation channel dTrpA1, also increased the male courtship index. This enhancement was abolished by the addition of the cry-GAL80 transgene. Our results highlight the phenomenon of increased male courtship activity caused by a magnetic field through CRY-dependent magnetic sensation in CRY expression neurons in Drosophila.

Social behavior and aging: A fly model

“…Courtship is an elaborate social behavior involving various sensory cues (eg, visual, auditory, olfactory, tactile) that can influence both the female's and male's behaviour. Even magnetic fields have recently been shown to increase male courtship activity, 207 highlighting the breadth of sensitivity this behavior has to variation in conditions. Many internal (eg, female sexual maturity 205 ) and external (eg, environmental conditions 206 ) factors can influence courtship and receptivity, and studies on courtship activity need be mindful of these influences on behavior.…”

“…Many internal (eg, female sexual maturity 205 ) and external (eg, environmental conditions 206 ) factors can influence courtship and receptivity, and studies on courtship activity need be mindful of these influences on behavior. Even magnetic fields have recently been shown to increase male courtship activity, 207 highlighting the breadth of sensitivity this behavior has to variation in conditions. Courtship is affected by aging.…”

Magnetic sensitivity mediated by the Arabidopsis blue-light receptor cryptochrome occurs during flavin reoxidation in the dark

“…Support for this suggestion has come from numerous studies in diverse organisms, where cryptochrome mutants are available. Using such mutants, it was possible to show that cryptochromes are required for effects of low-level MFs on growth and developmental responses in Arabidopsis (Ahmad et al 2007;Xu et al 2012Xu et al , 2014Xu et al , 2015 and on behavioral and physiological responses to low level applied MFs in Drosophila (e.g., Yoshii et al 2009;Foley et al 2011;Fedele et al 2014;Marley et al 2014;Wu et al 2016).…”

One Actor, Multiple Roles: The Performances of Cryptochrome in Drosophila

“…Cryptochrome is involved also in the modulation of other responses of Drosophila to the magnetic field. The courtship activity of wild-type males is significantly increased when they were exposed to a ≥20-Gauss static magnetic field (Wu et al, 2016), but not in cry-deficient mutants (cry b and cry M ) and in flies with CRY RNAi-mediated knockdown in cry-expressing FIGURE 3 | The role of CRY in molecular clock resetting. In the presence of light, CRY binds TIM and promotes its degradation via proteasome by a mechanism that involves the F-box protein JETLAG (JET).…”

“…neurons (Wu et al, 2016). Nevertheless, the phenotype is rescued when CRY is genetically expressed under the control of cry-Gal4 (Wu et al, 2016).…”