A novel pathway for Mus301 mediated DNA repair at Replication forks in Drosophila melanogaster
Hui, Carrie Ka
2012
- Scientists studying genome integrity are particularly interested in DNA double-stranded break repair. One gene that may be involved in DNA repair in Drosophila melantogaster is mus301. Previous research suggested a role for mus301 in homologous recombination (HR), but the mechanism by which Mus301 operates remains largely unknown. Through gene characterization, we report here that mus301 mutants ... read moreare sensitive to DNA damaging agents: topotecan and hydroxyurea, which are known for their role in causing stalled and collapsed forks. Sensitivity to these chemicals suggested that Mus301 operates at replication forks to repair damage. In addition we generated mus301, spn-A double mutants to study the role of mus301 in alternative end joining repair. Interestingly, these double mutants were homozygous lethal, suggesting that mus301 has a role outside of HR. To further understand the lethal phenotype we analyzed double mutant larvae development. The results from this analysis showed that double mutants were able to survive to first instar larvae, but death occurred rapidly after. Furthermore, to visualize damage in these mutants, we created mus301 homozygous, spn-A heterozygous mutants that were able to survive to third instar. Imaginal disc were collected from these mutants and cell death in these tissue was visualized with acridine orange. Results showed increased foci of damage in the mutants and in combination with the results from the double mutant development analysis this suggested that mus301, spn-A homozygous flies were unable to survive due to a defect in replication. From our results here, we propose a model in which Mus301 serves to unwind DNA structures at stalled replication forks to allow for replication to bypass the inhibition on the DNA template that originally caused the fork to stall or collapse.read less
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- j098zp16f
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- tufts:UA005.010.070.00001
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