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Updated: Sep 26, 2025
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High-throughput Screening for Protein-based Inheritance in S. cerevisiae
Published on: August 8, 2017
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Intron-mediated induction of phenotypic heterogeneity
Martin Lukačišin1,2,3, Adriana Espinosa-Cantú1, Tobias Bollenbach4,5
1Institute for Biological Physics, University of Cologne, Cologne, Germany.
Nature
|April 21, 2022
Summary
Introns in yeast ribosomal protein genes can create distinct cell populations with varied starvation survival strategies. This intron-mediated phenotypic heterogeneity offers a fitness advantage in changing environments.
Area of Science:
- Molecular Biology
- Genetics
- Eukaryotic Gene Regulation
Background:
- Introns are non-coding RNA sequences removed during transcript maturation, universally present in eukaryotic genomes.
- Budding yeast, typically intron-poor, possesses duplicated ribosomal protein genes with differing intron structures.
- Previous research highlighted ribosomal protein introns' roles in stress and starvation, but their contribution to ribosome regulation remained unclear.
Purpose of the Study:
- To investigate the role of introns in mediating inducible phenotypic heterogeneity and conferring fitness advantages in yeast.
- To elucidate how introns contribute to ribosome regulation and population diversification under environmental stress.
Main Methods:
- Combined isogrowth profiling and single-cell protein measurements.
- Analyzed bimodal gene expression of the small ribosomal subunit protein Rps22B.
- Investigated Rps22B expression under osmotic stress and high sugar concentrations.
Main Results:
- Osmotic stress induced bimodal Rps22B expression via a 5' untranslated region intron, creating subpopulations with differential starvation coping abilities.
- Low Rps22B levels promoted survival during sustained starvation; high levels accelerated growth after transient starvation.
- Yeast in high sugar conditions also showed bimodal Rps22B expression near the stationary phase.
Conclusions:
- Introns can mediate inducible phenotypic heterogeneity, providing a fitness advantage in dynamic environments.
- Differential intron-mediated regulation of ribosomal protein genes allows population diversification, aiding adaptation to environmental challenges like starvation.
- Duplicated ribosomal protein genes in yeast may balance precise expression control with environmental responsiveness.
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