Targeted methods for epigenetic age predictions in mice

Sci Rep. 2020 Dec 31;10(1):22439. doi: 10.1038/s41598-020-79509-2.

Abstract

Age-associated DNA methylation reflects aspect of biological aging-therefore epigenetic clocks for mice can elucidate how the aging process in this model organism is affected by specific treatments or genetic background. Initially, age-predictors for mice were trained for genome-wide DNA methylation profiles and we have recently described a targeted assay based on pyrosequencing of DNA methylation at only three age-associated genomic regions. Here, we established alternative approaches using droplet digital PCR (ddPCR) and barcoded bisulfite amplicon sequencing (BBA-seq). At individual CG dinucleotides (CpGs) the correlation of DNA methylation with chronological age was slightly higher for pyrosequencing and ddPCR as compared to BBA-seq. On the other hand, BBA-seq revealed that neighboring CpGs tend to be stochastically modified at murine age-associated regions. Furthermore, the binary sequel of methylated and non-methylated CpGs in individual reads can be used for single-read predictions, which may reflect heterogeneity in epigenetic aging. In comparison to C57BL/6 mice the single-read age-predictions using BBA-seq were also accelerated in the shorter-lived DBA/2 mice, and in C57BL/6 mice with a lifespan quantitative trait locus of DBA/2 mice. Taken together, we describe alternative targeted methods for epigenetic age predictions that provide new perspectives for aging-intervention studies in mice.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / genetics*
  • Animals
  • Computational Biology / methods
  • CpG Islands
  • DNA Methylation
  • Epigenesis, Genetic*
  • Epigenomics* / methods
  • Genetic Background
  • Genomics / methods
  • High-Throughput Nucleotide Sequencing
  • Mice
  • Real-Time Polymerase Chain Reaction