Data from: Avian offspring prenatal DNA methylation response to maternal corticosterone dosing during reproduction

Avian embryos develop in an egg composition which reflects both maternal
condition and the recent environment of their mother. In birds, yolk
corticosterone (CORT) influences development by impacting pre- and
postnatal growth, as well as nestling stress responses and development.
One possible mechanism through which maternal CORT may affect offspring
development is via changes to offspring DNA methylation. We sought to
investigate this, for the first time in birds, by quantifying the impact
of manipulations to maternal CORT on offspring DNA methylation. We
non-invasively manipulated plasma CORT concentrations of egg-laying female
zebra finches (Taeniopygia castanotis) with an acute dose of CORT
administered around the time of ovulation and collected their eggs. We
then assessed DNA methylation in the resulting embryonic tissue and in
their associated vitelline membrane blood vessels, during early
development (5 days after lay), using two established methods - liquid
chromatography–mass spectrometry (LC-MS) and methylation-sensitive
amplification fragment length polymorphism (MS-AFLP). LC-MS analysis
showed that global DNA methylation was lower in embryos from CORT-treated
mothers, compared to control embryos. In contrast, blood vessel DNA from
eggs from CORT-treated mothers showed global methylation increases,
compared to control samples. There was a higher proportion of global DNA
methylation in the embryonic DNA of second clutches, compared to first
clutches. Locus-specific analyses using MS-AFLP did not reveal a treatment
effect. Our results indicate that an acute elevation of maternal CORT
around ovulation impacts DNA methylation patterns in their offspring. This
could provide a mechanistic understanding of how a mother’s experience can
affect her offspring’s phenotype.