Lack of increases in methylation at three CpG-rich genomic loci in non-mitotic adult tissues during aging
2007

Methylation Changes in Adult Tissues During Aging

Sample size: 21 publication Evidence: moderate

Author Information

Author(s): Michelle W. Chu, Kimberly D. Siegmund, Carrie L. Eckstam, Jung Yeon Kim, Allen S. Yang, Gary C. Kanel, Simon Tavaré, Darryl Shibata

Primary Institution: University of Southern California Keck School of Medicine

Hypothesis

Somatic genomes may record their mitotic ages through accumulation of replication errors reflected in DNA methylation.

Conclusion

Methylation changes at certain CpG rich regions appear to represent replication errors, indicating that mitotic ages are recorded in somatic cell genomes.

Supporting Evidence

  • Significant increases in DNA methylation were observed in adult compared to fetal or newborn tissues for two of the three examined tags.
  • Adult tissues showed no significant increases in tag methylation after infancy, consistent with low cell division rates.
  • Different tissues exhibited varying levels of tag methylation, reflecting their genealogies and mitotic ages.

Takeaway

As we grow older, our cells make mistakes when copying their DNA, and these mistakes can be seen in certain parts of our genes.

Methodology

DNA methylation patterns were measured using bisulfite sequencing from heart, brain, kidney, and liver tissues of 21 individuals of different ages.

Potential Biases

Potential biases may arise from the mixed cell types in the tissue samples analyzed.

Limitations

The study's findings may not apply to all tissues, and the exact mechanisms of methylation changes are uncertain.

Participant Demographics

The study included 21 individuals of varying ages, with a mix of sexes and causes of death.

Statistical Information

P-Value

p<0.05

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1186/1471-2350-8-50

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