Non-visual light modulates behavioral memory and gene expression in C. elegans.

Area of Science:

• * Non-neuronal light sensing
• * Molecular biology
• * Behavioral genetics

Background:

• * Animals possess sophisticated visual systems to perceive light.
• * Non-visual light responses and their underlying mechanisms are poorly understood.
• * Light influences physiological processes beyond vision.

Purpose of the Study:

• * To investigate light-induced physiological responses independent of the visual system in *C. elegans*.
• * To identify the genetic pathways mediating non-visual light responses.
• * To explore the role of light in modulating behavioral plasticity.

Main Methods:

• * Gene expression analysis in *C. elegans* exposed to visible light.
• * Investigating the role of bZIP transcription factors (ZIP-2, CEBP-2) and the *cyp-14A5* gene.
• * Utilizing controlled-intensity visible-spectrum LEDs and wavelength-specific light exposure.
• * Employing genetic manipulation to drive ectopic gene expression.

Main Results:

• * A novel light-induced transcriptional pathway activating *cyp-14A5* in non-neuronal tissues was identified.
• * This pathway is mediated by bZIP transcription factors ZIP-2 and CEBP-2.
• * Light induction of *cyp-14A5* is wavelength-dependent (shorter wavelengths more potent) and independent of known blue light receptors (LITE-1, GUR-3).
• * The pathway enhances behavioral adaptability and olfactory memory, suggesting a body-brain communication axis.
• * Ectopic expression driven by the *cyp-14A5* promoter induced synthetic light-induced sleep and rapid aging phenotypes.

Conclusions:

• * *C. elegans* possesses a non-visual light-sensing pathway in non-neuronal tissues.
• * This pathway, involving *cyp-14A5*, ZIP-2, and CEBP-2, modulates behavioral plasticity and memory.
• * Findings suggest a body-brain communication axis mediated by light.
• * The *cyp-14A5* promoter provides a tool for inducible gene expression in non-neuronal tissues.