Differential DNA methylation landscapes in the hippocampus of socially dominant and submissive mice during postnatal development

Background: Social behavior in rodents have been widely studied and the critical roles of parameters such as environment and maternal care were highlighted. It was shown before that poor maternal care have long-term effects on the DNA methylation landscape in the adult offspring. However, it is less clear if and which changes in the DNA methylation landscape occur throughout early postnatal developmental stages.
Methods: We used mouse models of social dominance (Dom) and submissiveness (Sub), who show innate features of high and low maternal care behaviors, respectively. For genome-wide DNA methylation analysis we used reduced-representation bisulfite sequencing (RRBS-Seq ) of hippocampal DNA from 7- and 21-days-old Sub and Dom pups.
Results: We found robust alterations in the DNA methylation landscape for both between-group and between timepoint analyses; with significant enrichment of differentially methylated CpGs in gene promoters encoding for genes associated with behavior, and neuronal development.
Conclusion: We conclude that altered methylome previously reported in the hippocampus of adult offspring is precede by early and time-dependent post-natal changes in DNA methylation patterns, highlighting the importance of early-life interventions.