Poor, Bare, Forked Animals Begin to Decipher Epigenome

NIH
The epigenome is the system of genome modifiers that guide gene expression. Epigenetics determines whether a cell will be a brain cell or a liver cell, even though both cells possess the same genome. Some preliminary results are beginning to come in from the US NIH's modENCODE program.

Sarah C.R. Elgin, PhD, the Viktor Hamburger Distinguished Professor in Arts & Sciences, who led the Washington University lab that is part of one of the modENCODE teams offers an explanation.

“We learned many things from the Human Genome Project,” Elgin says, “but of course it didn’t answer every question we had!

“Including one of the oldest: We all start life as a single cell. That cell divides into many cells, each of which carries the same DNA. So why are we poor, bare, forked creatures, as Shakespeare [Al Fin: Lear ActIII SceneIV] put it, instead of ever-expanding balls of identical cells?

“This work,” says Elgin, “will help us learn the answer to this question and to many others. It will help us to put meat on the bones of the DNA sequences.” _WUNewsroom

Wikipedia

The epigenetic code that determines whether genes are silenced or expressed consists of chemical modifications to the DNA, to “tails” that hang off the histones, or other packaging proteins.

“ENCODE and modENCODE are much more complicated projects than the Human Genome Project,” Elgin says, “because the DNA sequence is pretty much the same in every cell type, whereas the chromatin structure is different in every cell type. In fact we believe it is the chromatin structure that differentiates one cell type from another.

“That means we can’t just do one genome for the organism. We have to do every different cell type to get a complete picture of the organism, and that’s a daunting prospect.” _WU

The research relies upon the most advanced bio-research and computing technologies. The amount of data generated is staggering, and far beyond what an unaided human could organise and comprehend.

But this is the beginning of the true meat of genetics. Sure, they are looking at worms and fruit flies now. But humans and all human symbionts and parasites are on the list to be comprehensively studied. The knowledge to be gained will provide unimaginable benefits.