Light controls gene functions through alternative splicing in fungi

Area of Science:

• Mycology
• Molecular Biology
• Biochemistry

Background:

• Light is a crucial environmental signal regulating fungal gene expression.
• Fungal responses to light involve transcriptional control, but post-transcriptional regulation remains less understood.

Purpose of the Study:

• To investigate the role of light in regulating alternative splicing (AS) in filamentous fungi.
• To elucidate the molecular mechanisms linking light perception to AS regulation.

Main Methods:

• Comparative analysis of gene expression and AS patterns under different light conditions.
• Genetic manipulation of key signaling pathway components (BLR1, Sak, SRK1, SRP1).
• Biochemical assays to determine protein localization and phosphorylation status.

Main Results:

• Light, specifically blue light, regulates AS in *Aspergillus nidulans*, *Trichoderma guizhouense*, and *Neurospora crassa*.
• Blue light-induced AS in *T. guizhouense* affects ergothioneine biosynthesis and conidiation, mediated by the BLR1 receptor.
• A signaling cascade involving the MAPK HOG (Sak) pathway, SRK1, and SRP1 transmits the light signal to the splicing machinery, regulating AS efficiency and light-induced conidiation.

Conclusions:

• Light regulates fungal biology at the post-transcriptional level through alternative splicing.
• A novel signaling pathway connects environmental light signals to the fungal splicing machinery, influencing development and metabolism.
• This discovery adds a new layer to understanding fungal environmental sensing and response mechanisms.