Tissue-specific differences in the accumulation of sequence rearrangements with age
Dominika M Wiktor-Brown1, Werner Olipitz, Carrie A Hendricks
1Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States.
DNA Repair
|March 25, 2008
Summary
Homologous recombination (HR) repair of DNA damage shows age-related increases in pancreas but not skin. Tissue-specific differences in cell persistence, not HR capacity, likely explain this.
Area of Science:
- Molecular Biology
- Genetics
- Aging Research
Background:
- Mitotic homologous recombination (HR) is crucial for DNA double-strand break (DSB) repair.
- Errors in HR can lead to sequence rearrangements, contributing to cancer and aging.
- Understanding tissue-specific HR during aging is vital.
Purpose of the Study:
- To investigate age-related changes in homologous recombination (HR) across different tissues.
- To determine if observed differences are due to HR rates or recombinant cell persistence.
Main Methods:
- Utilized Fluorescent Yellow Direct Repeat (FYDR) mice to track HR events.
- Compared recombinant cell frequency in various tissues (pancreas, skin) of aged vs. young mice.
- Performed in vitro studies on primary fibroblasts from different age groups.
Main Results:
- Significant age-related increase (23-fold) in recombinant cell frequency in the pancreas.
- No significant increase in recombinant cell frequency in the skin in vivo.
- Juvenile and aged fibroblasts showed similar HR capabilities in vitro.
Conclusions:
- Tissue-specific accumulation of recombinant cells with age is observed.
- The lack of accumulation in skin is not due to impaired HR capacity.
- Differences in recombinant cell persistence and clonal expansion likely drive tissue-specific aging patterns.
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