The next leap forward since mapping the human genome?

Image credit: Jonathan Bailey, NHGRI

Last week, when news broke that scientists had mapped over a hundred epigenomes – an effort being hailed as the next leap forward since the sequencing of the human genome more than a decade ago – I was excited.  Thrilled, even, for the burgeoning field of epigenomics, which apparently is advancing at an unprecedented pace.  But truthfully, I was unclear why this latest development was so significant and worse still – especially for the purposes of writing this post – clueless as to the meaning of the term epigenome; I’m afraid it wasn’t covered in the biology survey I took in college, and if it had been, well, it probably wouldn’t have stuck.

So, when I reached out to Dr. Bing Ren of the University of California, San Diego, member of the Ludwig Institute for Cancer Research and one of the many researchers involved in this comprehensive study, I was mildly concerned he wouldn’t be able to explain matters in terms I could readily understand.  Therefore, I thought it best to first consult a short video using metaphor.  The sheet music in this analogy represents our DNA — that is, the genetically encoded information found in our cells.  How each cell reads these musical notes can vary widely, which accounts for the many ways cells go on to differentiate.  This variation results from chemical changes to the DNA and the proteins that DNA wraps itself around, and it is these modifications that are referred to as the epigenome (feel free to watch the video and to challenge my synopsis in the comment section below).

Chromatin

Click to enlarge | Image credit: Darryl Leja, NHGRI

Dr. Manolis Kellis, a professor at MIT and leading figure behind the epigenome initiative, no doubt explains things more elegantly, comparing the human genome to “the book of life,” which our cells read in different ways, “bookmarking different pages and highlighting different paragraphs and words.”

So, epigenomics offers a far more dynamic look at our genes with the potential to “help uncover the genetic basis of human traits and diseases,” added Ren.

Indeed, one of the most intriguing of these findings relates to the epigenetic changes occurring with the onset of Alzheimer’s disease.  Kellis and his colleagues were surprised to discover that the genetic variants associated with Alzheimer’s are active in immune cells and not neural processes as once suspected.  This finding could fundamentally change the way we understand and treat AD.  And not just Alzheimer’s.  The project is shedding new light on cancer, diabetes, MS, and arthritis.

What makes these findings particularly compelling is the sheer amount of data on which they are founded.  Specifically?  Nearly 3,000 datasets generated by researchers from four different production centers.  It was a massive interdisciplinary effort beginning in 2008, explains Ren, which was reliant on recent advancements in sequencing technologies, as well as significant reductions in costs to employ them.

Perhaps what is most exciting about the project is that all of the data it generated has been made available to the public. “Therefore, even though the program has ended,” says Ren, “the discoveries are just beginning.”