Epigenética: desembrulhando o genoma e fortalecendo o design inteligente?

quarta-feira, janeiro 06, 2016

Epigenetics: The genome unwrapped

Heidi Ledford

Nature 528, S12–S13 (03 December 2015) doi:10.1038/528S12a

Published online 02 December 2015

Epigeneticists are harnessing genome-editing technologies to tackle a central question hanging over the community — does their field matter?

Source/Fonte: Kyle Bean-Nature

Subject terms: Biological techniques Epigenetics Drug discovery

On 18 February, a consortium of more than 90 laboratories published a landmark catalogue of the chemical changes to DNA that are thought to influence whether and how genes are expressed. Called the Roadmap Epigenomics Project and sponsored by the US National Institutes of Health, the compendium offered an unprecedented look at the layers of coding that exist on top of the genetic code — collectively known as the 'epigenome' — in 127 different human tissues and cell types. The US$154-million project was viewed as a crucial step towards determining how this chemical code contributes to human health and disease. As researchers get to grips with the catalogue's contents, the project is also likely to provide a leap forward in pinning down one of the central mysteries of biology: how do cells with the same genetic instructions take on wildly different identities?

It is still unclear what that epigenetic code actually does, and how it is generated. “I don't think it can be overstated how little we understand about how the epigenome works,” says Charles Gersbach, a biomedical engineer at Duke University in Durham, North Carolina. “There are all of these epigenetic marks and we don't know what they are doing. Are they even necessary?”

After years of wondering, biologists such as Gersbach are now in a position to find out. By harnessing genome-editing technologies, they are able to interrogate the epigenetic control of gene expression with remarkable power and specificity. Researchers can make or delete epigenetic marks at will, and home in on RNAs and proteins that could play a hitherto unrecognized part in directing gene expression. And with these new capabilities, they hope to build an answer to a key question that has plagued the field of epigenetics since its inception — do epigenetic marks alter gene expression or do changes in gene expression alter the marks? “It's an absolutely legitimate question and we need to address it,” says Luca Magnani, a cancer researcher at Imperial College London. “The answer is either going to kill the field, or make it very important.”