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Updated: Jun 28, 2026
A Deep-sequencing-assisted, Spontaneous Suppressor Screen in the Fission Yeast Schizosaccharomyces pombe
Published on: March 7, 2019
A screening for suppressor mutants reveals components involved in the blue light-inhibited sexual filamentation in
Yu-Ling Yeh1, Yu-Sheng Lin, Bei-Jia Su
1Department of Plant Pathology and Microbiology, National Taiwan University, Room 216, Building Number 1, No. 1 Roosevelt Road, Sec. 4, 10617 Taipei, Taiwan.
Abstract:
Blue light regulates diverse physiological and developmental processes in fungi. Our prior studies demonstrated that the evolutionally conserved Cwc1 and Cwc2 proteins mediate the blue light-inhibited sexual filamentation in Cryptococcus neoformans. To characterize the putative domains of the Cwc1 and Cwc2 proteins, we generated partially deleted versions of these genes under the GPD1 promoter and examined their effects. The results confirmed that LOV and PAS domains are essential for the function of the Cwc1 protein, and the PAS domain and zinc finger DNA-binding motif are also crucial for the Cwc2 protein. To further understand how light inhibits filamentous growth, a genome wide mutant screening was conducted to identify genes important for this process. Mutants which suppressed the light-dependent CWC1 overexpression phenotype and restored mating filamentation were identified. In the one with fully restored filamentation, the T-DNA was found to disrupt the expression of the CWC2 gene. Additionally, a mediator component, the SSN8 gene, known to involve in transcriptional regulation was also identified. Our results demonstrate that Cwc1 and Cwc2 are two central regulators of the C. neoformans photoresponses and the roles of other components identified in the screen are under investigation.
Insights
Blue light controls fungal development. The Cwc1 and Cwc2 proteins are key regulators of blue light-inhibited sexual filamentation in Cryptococcus neoformans, with specific domains being essential for their function.
Area of Science:
- Mycology
- Molecular Biology
- Photobiology
Background:
- Blue light influences fungal physiology and development.
- The conserved Cwc1 and Cwc2 proteins regulate blue light-inhibited sexual filamentation in Cryptococcus neoformans.
Purpose of the Study:
- To characterize the functional domains of Cwc1 and Cwc2 proteins.
- To identify genes involved in blue light-mediated inhibition of filamentous growth in C. neoformans.
Main Methods:
- Generation and analysis of partially deleted Cwc1 and Cwc2 gene versions.
- Genome-wide mutant screening to identify suppressors of light-dependent CWC1 overexpression.
- T-DNA insertion analysis and gene expression studies.
Main Results:
- LOV and PAS domains are essential for Cwc1 function.
- PAS domain and zinc finger DNA-binding motif are crucial for Cwc2 function.
- Disruption of CWC2 restored mating filamentation in a mutant.
- The SSN8 gene, involved in transcriptional regulation, was identified as a mediator component.
Conclusions:
- Cwc1 and Cwc2 are central regulators of C. neoformans photoresponses.
- Specific protein domains and regulatory pathways are critical for light-mediated growth inhibition.
