The Promise of Paleo-Epigenetics
Thanks to new research in the field of ancient DNA, we are now a step closer to understanding how ancient environments and cultural practices may have affected the health of people living in past societies. This new research applies the field of epigenetics, the study of heritable chemical modifications to DNA in response to the environment, to ancient human populations. “Paleo-epigenetics” has the potential to give us fascinating new insights into the lives of our ancestors.
The development of a human is a complex process, depending on not just which alleles (forms of a gene) are present in their genome, but also when and where genes are expressed (when the information stored in DNA sequences is converted to the proteins that make up the human body). Different genes are expressed at varying stages of an organism’s development and are expressed by diverse kinds of cells (for example, neurons express different genes than skin cells, even though they have the same DNA sequence). In addition, genes may vary in expression throughout an organism’s lifetime, responding to changes in its environment.
This process is regulated in multiple ways at different stages of gene expression. The transcription stage (DNA-> mRNA) is one of the most important stages of regulation, and one of the ways it is regulated is by chemical modifications to DNA that either direct the cell to begin expression, or to silence the genetic information in that region. These chemical “tags” or “marks”, such as the addition of methyl groups to the DNA base cytosine, don’t change the DNA sequence itself, just whether or not it is expressed. For a really nice video explanation of epigenetics, check out this page.
Some types of epigenetic modifications are directly influenced by environmental factors. Thus, characterizing and understanding the “epigenome” can help —> Read More