“Over the past 60 years, we have increasingly relied on artificial light sources that emit much narrower wavelength spectrums than does the sun. Yet, little research has been conducted to determine gene expression consequences, if any, from the use of common artificial light sources.”
Texas State University research shows genome wide changes in the gene expression of patterns in skin, brains, and liver following exposure to white fluorescent light exhibiting increased inflammation and immune responses in mice and fish studies, as published in the journal Genes.
“Evolution occurred over many millennia exclusively under the full spectrum of sunlight. Thus, life had the opportunity to conscript each wavelength in the solar spectrum for the regulation of specific gene expression pathways,” explains Christi Walter.
Fluorescent light wavelength activated genes were identified using zebrafish, Japanese rice fish, and hairless mice; increased inflammation was present in tissues and organs regardless of whether the animal was primarily active in the day or night.
Increased inflammation and immune responses was observed in skin and brains of all animals, as well as in the liver of both fish species, but reaction in the liver was suppressed in mice models; results suggest the presence of light responsive genetic circuitry is deeply embedded in the vertebrate genome.
“In this report, we show genome-wide changes of gene expression patterns in skin, brain and liver for two commonly utilized fish experimental models (zebrafish and Japanese rice fish, also known as medaka), and a mammalian (mice), following exposure to 4,100 K ‘cool-white’ fluorescent light,” says Walter. “In spite of the extreme divergence of these animals (i.e., estimated divergence of mice and fish about 450 million years), and drastically different lifestyles (i.e., diurnal fish and nocturnal mice), the same highly conserved primary genetic response that involves activation of inflammation and immune pathways as part of an overall acute phase response was observed in the skin, brain and liver of all three animals. Follow-up studies to further define this response in mice are underway.”
These genes under broad spectrum daylight conditions are hypothesized by the researchers to be subsequently deactivated by wavelengths from different parts of the spectrum, but the wavelengths may be absent in fluorescent lighting, which may be revealed in future research.
