Ribosomal RNA Gene Silencing in Nucleolar Dominance
Author Information
Author(s): Michelle S. Lewis, Diane J. Pikaard, Mikhail Nasrallah, Jed H. Doelling, Craig S. Pikaard
Primary Institution: Washington University, Saint Louis, Missouri, United States of America
Hypothesis
Is nucleolar dominance the result of individual rRNA gene silencing or is it dependent on the nucleolus organizer regions?
Conclusion
The study suggests that rRNA gene activation can occur independently of chromosomal location, while silencing in nucleolar dominance is locus-dependent.
Supporting Evidence
- Transgenes were accurately transcribed in all independent transgenic Arabidopsis thaliana lines tested.
- Endogenous rRNA genes located within the A. thaliana NORs are silenced in hybrids.
- rRNA transgenes escaped silencing in multiple independent hybrids.
Takeaway
This study shows that some genes can be turned off or on depending on where they are located in the genome, especially in plant hybrids.
Methodology
Transgenic Arabidopsis thaliana lines were created and crossed with A. lyrata to study rRNA gene expression and silencing.
Limitations
The study does not fully distinguish between nucleolar dominance-related mechanisms and other potential transgene silencing mechanisms.
Digital Object Identifier (DOI)
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