Research focusing on epigenetic modifications is a growing field in the neuroscience area. However, issues related to data reproducibility across laboratories remain. For example, separating meaningful experimental changes from background variability is a challenge in epigenomic studies. In this article, Detlev Boison and colleagues show that seemingly minor experimental variations, even under normal baseline conditions, can have a significant impact on epigenome outcome measures and data interpretation. The authors examined genome-wide DNA methylation and gene expression profiles of hippocampal tissues from wild-type rats housed in three independent laboratories using nearly identical conditions. The analysis identified 3852 differentially methylated and 1075 differentially expressed genes between laboratories, even in the absence of experimental intervention.
This finding is particularly meaningful for neurological studies in animal models, in which baseline parameters between experimental groups are difficult to control. To enhance scientific rigor, the authors conclude that strict adherence to protocols is necessary for the execution and interpretation of epigenetic studies and that protocol-sensitive epigenetic changes, amongst naive animals, may confound experimental results.