Telomere length and DNA methylation (DNAm) are two promising biomarkers
of biological age. Environmental factors and life history traits are
known to affect variation in both these biomarkers, especially during
early life, yet surprisingly little is known about their reciprocal
association. Here, we present the first study on a natural population to
explore how variation in DNAm, growth rate and early-life conditions are
associated with telomere length changes during development. We tested
these associations by collecting data from wild, nestling zebra finches
in the Australian desert. We found that increases in the level of DNAm
were negatively correlated with telomere length changes across early
life. We also confirm previously documented effects of post hatch growth
rate and clutch size on telomere length in a natural ecological context
for a species that has been extensively studied in the laboratory.
However, we did not detect any effect of ambient temperature during
developmental on telomere dynamics. We also found that the absolute
telomere length of wild zebra finches, measured using the in-gel TRF
method, was similar to that of captive birds. Our findings highlight
exciting new opportunities to link and disentangle potential
relationships between environmental, epigenetic and telomere length
dynamics during early life.
Associations between DNA methylation and telomere length during early life: Insight from wild zebra finches (
Taeniopygia guttata
)
