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In Vivo Forward Genetic Screen to Identify Novel Neuroprotective Genes in Drosophila melanogaster
Published on: July 11, 2019
Defining genetic factors that modulate intergenerational CAG repeat instability in Drosophila melanogaster
Joonil Jung1, Marijn T M van Jaarsveld, Shin-Yi Shieh
1Department of Biology and the Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6018, USA.
Genetics
|November 3, 2010
Summary
This study introduces an enhanced fruit fly model to investigate trinucleotide repeat instability, a key factor in hereditary neurological disorders. Findings reveal that pathogenic polyglutamine proteins can globally influence repeat instability, identifying new genetic modifiers.
Area of Science:
- Genetics
- Molecular Biology
- Neuroscience
Background:
- Trinucleotide repeat instability causes over 20 hereditary disorders, including neurological and neurodegenerative diseases.
- Pathogenic polyglutamine (polyQ) domains, encoded by expanded CAG repeats, are implicated in these conditions.
- Understanding repeat instability mechanisms is crucial but limited by the lack of unbiased genome-wide screens in complex organisms.
Purpose of the Study:
- To develop and utilize an enhanced Drosophila melanogaster model for studying trinucleotide repeat instability.
- To investigate the potential global modulation of repeat instability by pathogenic polyQ proteins in vivo.
- To perform an unbiased genetic screen to identify novel modifiers of CAG repeat instability.
Main Methods:
- Development of an enhanced fly model with a noncoding 270 CAG repeat construct (UAS-CAG(270)) under germline-specific promoter control.
- Assessment of repeat instability in the enhanced fly model.
- In trans modulation experiments using pathogenic polyQ protein expression.
- Unbiased genetic screening for modifiers of CAG repeat instability.
Main Results:
- The enhanced fly model exhibits substantial trinucleotide repeat instability.
- Expression of pathogenic polyQ proteins modulates CAG(270) repeat instability in trans, suggesting a global effect in vivo.
- The genetic screen identified CG15262, a protein containing a NOT2/3/5 conserved domain, as a modifier of CAG repeat instability.
- Different facets of repeat instability appear to be independently genetically regulated.
Conclusions:
- Pathogenic polyglutamine proteins may globally influence genome-wide repeat instability.
- The identified genetic modifiers, including CG15262, offer new targets for understanding and potentially treating trinucleotide repeat expansion disorders.
- This enhanced fly model provides a powerful platform for future unbiased genetic screens in multicellular eukaryotes.
