Last week, a new study was published in the open-access online journal eLife, titled “Differential methylation between ethnic sub-groups reflect the effect of genetic ancestry and environmental exposures”. As frequently occurs with new research findings, a summary of the study was written on the popular science website, IFLScience.

The author of this article did a good job of summarizing a key concept that we have discussed in this course: how cells with the same genetic material can develop into different cell types with various functions. One of the ways in which this can happen, the author states, is through the addition of methyl groups to DNA, which can alter gene expression patterns. From there, he went on to explain how different environmental factors can alter the methylation patterns within the cell, using the example of smoking. This provided the key background information necessary to understand the results of the study, which showed that some differences in methylation were associated with ethnicity, rather than shared ancestry. As race/ethnicity are known to be social constructs, the authors concluded that a shared environment or culture could be at play in mediating these patterns.

However, there were some scientific missteps within this article. The most egregious error occurred when the author equated “epigenetics” with “methyl groups”, which is an oversimplification of the epigenetic controls over DNA. As we know, epigenetic alteration is not limited to DNA methylation. Many different covalent modifications can be added to nucleotides, as well as to the histone proteins contained within the nucleosome. Furthermore, there are epigenetic mechanisms such as miRNAs that do not involve the covalent modification of genetic elements at all. Granted, this is a complex field that could not be entirely explained in a short article, but the author could still have mentioned that there are mechanisms other than DNA methylation that are involved in epigenetic regulation of gene expression. This goes to show that as members of the scientific community, we should sometimes be cautious about news reports surrounding research studies, and look instead to the primary literature for the real answers.