Related Experiment Videos
Fast light-regulated genes of Neurospora crassa
T Sommer1, J A Chambers, J Eberle
1Max-Planck-Institut für Molekulare Genetik, Abteilung Trautner, Berlin, FRG.
Abstract:
Several physiological reactions including the sexual differentiation of the ascomycete Neurospora crassa are triggered by blue light. Mutants in the white-collar genes wc-1 and wc-2 are blind for all the blue light effects tested so far. We have previously shown that blue light induces some translatable mRNAs at different times after beginning the illumination. Here we report the cDNA cloning of four genes that are induced by blue light. Induction of these transcripts is temporally ordered (lag times from 2 to 45 min). Analysis of run-on transcripts show that the increases in mRNA levels are due to de novo transcription. None of these transcripts is inducible in white-collar mutants.
Insights
Blue light triggers physiological responses in Neurospora crassa, including sexual differentiation. Researchers identified four blue light-induced genes, demonstrating their dependence on white-collar genes for induction.
Area of Science:
- Molecular Biology
- Mycology
- Photobiology
Background:
- Blue light influences numerous physiological processes in the ascomycete Neurospora crassa.
- Mutations in white-collar genes (wc-1 and wc-2) abolish responses to blue light.
- Previous work indicated blue light-induced translatable mRNAs.
Purpose of the Study:
- To clone and characterize genes transcriptionally regulated by blue light in Neurospora crassa.
- To investigate the temporal dynamics of blue light-induced gene expression.
- To determine the role of white-collar genes in mediating blue light responses.
Main Methods:
- cDNA library construction and screening.
- Northern blot analysis to assess mRNA levels.
- Run-on transcription assays to measure de novo transcription rates.
Main Results:
- Four distinct cDNA clones representing blue light-induced transcripts were isolated.
- Transcriptional induction occurred in a temporally ordered manner, with lag times ranging from 2 to 45 minutes.
- Run-on assays confirmed that increased mRNA levels result from de novo transcription.
- Induction of these transcripts was completely abolished in white-collar mutants (wc-1 and wc-2).
Conclusions:
- Blue light regulates gene expression in Neurospora crassa through transcriptional activation.
- White-collar genes (wc-1 and wc-2) are essential components of the blue light signaling pathway.
- The identified genes represent downstream targets of the white-collar gene regulatory complex.