Wavelengths and irradiances modulate the circadian rhythm of Neurospora crassa

Abstract

The circadian rhythm affects the biological evolution and operating mechanisms of organisms. The impact of light on the circadian rhythm is a significant concern for both biology and human well-being. However, the relation between different wavelengths, irradiances, and circadian rhythm is unknown. In this study, we compared the effects of four different monochromatic light-emitting diode (LED) light and two different irradiances on the circadian rhythm of a wild-type Neurospora crassa. The results demonstrated that the circadian rhythm of Neurospora crassa can be modulated by violet (λp = 393 nm), blue (λp = 462 nm), and green (λp = 521 nm) light, regardless of the irradiances, in the visible region. Unexpectedly, for the yellow light (λp = 591 nm), the 2 W/m2 light had a more significant impact on circadian rhythm modulation than the 0.04 W/m2 light had. Considering the highest energy of yellow light (2.25 eV) is lower than the High Occupied Molecular Orbital (HOMO)-Lowest Unoccupied Molecular Orbital (LUMO) gap of WC-1 (2.43 eV). We speculate that there may be other potential photoreceptors that are involved in circadian rhythm modulation. The HOMO-LOMO gaps of these proteins are greater than 1.98 eV and less than 2.25 eV. These results provide a strong foundation for a deeper understanding of the impact of different light on the circadian rhythm and also shed light on the identification of new circadian rhythm modulation photoreceptors.

Proper use of light environments for mitigating the effects of COVID-19 and other prospective public health emergency lockdowns on sleep quality and fatigue in adolescents

“…Studies on children [ 29 ] and adolescents [ 30 ] have shown that exposure to a high CCT light environment in the evening could affect sleep quality and reduce sleepiness, compared with a low CCT light environment. Previous studies have further indicated that high CCT light could affect circadian rhythm [ [31] , [32] , [33] ] and influence sleep quality [ 34 ]. Further, in the current study, of the positive effect of low CCT light on sleep quality in adolescents was significant and prominent from the first day of the light intervention.…”