Epigenetic age estimation of wild mice using faecal samples.

Area of Science:

• Ecology
• Genetics
• Animal Biology

Background:

• Accurate age estimation is crucial in animal ecology, but non-lethal methods are challenging.
• Epigenetic clocks offer a promising non-lethal approach for age estimation in wildlife.
• Current epigenetic clocks often rely on invasive samples and lack validation across different environments.

Purpose of the Study:

• To develop a targeted epigenetic clock using non-invasive fecal samples from laboratory mice.
• To assess the accuracy of this lab-derived clock in estimating the age of wild mice.
• To compare epigenetic methylation patterns and age estimates between wild and laboratory mice.

Main Methods:

• A targeted epigenetic clock was developed using DNA from fecal samples of laboratory mice (Mus musculus).
• The developed clock was applied to estimate the age of wild mice (Mus musculus domesticus).
• Epigenetic age estimates and methylation patterns were compared between wild and laboratory mice, considering body mass.

Main Results:

• The laboratory mouse-derived epigenetic clock successfully differentiated between juvenile and adult wild mice.
• Wild mice exhibited an increase in epigenetic age over time, with significant individual variation in aging rates.
• Wild mice consistently showed higher CpG methylation and epigenetic age estimates than laboratory mice, even at similar body masses.

Conclusions:

• Non-invasive epigenetic clocks can be developed from laboratory animals for use in wild populations.
• Significant differences in methylation patterns and epigenetic aging exist between wild and laboratory mice.
• Caution is advised when applying epigenetic clocks developed in laboratory settings to wild animals due to potential environmental influences.