RNA-mediated recombination in S. cerevisiae.
L K Derr1, J N Strathern, D J Garfinkel
1Laboratory of Eukaryotic Gene Expression, NCI-FCRDC, Frederick, Maryland 21702.
Cell
|October 18, 1991
Summary
RNA-mediated recombination was demonstrated in yeast using a HIS3 reporter. This process, requiring transcription and retrotransposon Ty expression, leads to intron loss and pseudogene formation.
Area of Science:
- Molecular Biology
- Genetics
- Yeast Biology
Background:
- Pseudogenes and intron loss suggest RNA's role in recombination.
- Understanding RNA-mediated recombination is crucial for gene regulation and evolution.
Purpose of the Study:
- To investigate RNA-mediated recombination in yeast.
- To demonstrate the mechanism of intron loss and pseudogene formation via RNA intermediates.
Main Methods:
- Utilized a HIS3 reporter gene system in yeast.
- Required transcription and expression of the retrotransposon Ty.
- Analyzed recombination events through prototroph formation and DNA sequencing.
Main Results:
- Confirmed RNA-mediated recombination in yeast.
- Observed homologous recombination leading to intron loss.
- Detected cDNA insertion into chromosomes, creating pseudogene-like structures.
- Characterized chromosomal prototrophs with hallmarks of natural pseudogenes (novel integration sites, intron loss, poly(A) tracts).
Conclusions:
- RNA can act as an intermediate in homologous recombination and gene integration.
- The retrotransposon Ty plays a role in facilitating RNA-mediated recombination.
- This study provides a model for understanding pseudogene formation and intron loss in eukaryotes.
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