What is epigenomics?

[aenon]

First we thought the genome would let us know everything about ourselves and lead to personalized medicine. Now we have the epigenome: chemical modifications in the DNA that affect what information is used from it, without changing the information content.

Epigenomic changes can happen because of our environment, stress, ... and in some cases it is the cause of different kinds of cancers.

Below is a link that aims at explaining what it is and how it can affect our lives.

What do you think about it?

You can't always blame your parents

[Endy0816]

Yeah, epigenetic changes are interesting. Makes sense for life to have more tricks in its toolkit than the fairly static DNA.

 

Do wish we understood the mechanisms better. Seems like we could get some decent use out of it without messing with(or messing up) the underlying DNA.

[CharonY]

Usually epigenetics falls into the broader range of regulatory control. As such it is not a completely new phenomenon, as due to their very nature regulatory mechanisms are highly dynamic. It is in the end a oversimplified view that DNA alone would tell us the whole story, and researchers were very aware of that from the beginning.

[chadn737]

Epigenomics is not epigenetics. This is a matter of quite a lot of contention, as "epigenetic" has been used so loosely in recent years that many confuse it with environmental effects or as being synonymous with something like histone modifications and DNA methylation.

 

Epigenomics as a whole refers to direct chemical modification of DNA, such as DNA methylation, and the proteins that make up chromatin and their modifications.

 

Epigenetics is the transgenerational inheritance of non-genetic factors. The key here being that it is heritable. Most epigenomic modifications in Mammals are erased in each generation and so are not epigenetic. The situation is different in plants. However, many epigenomic variants in plants are directly or indirectly caused by genetic variants and so not truly epigenetic either. This is why the distinction is important.

 

This distinction also has the useful characteristics in that it immediately eliminates the vast majority of environmentally induced epigenomic variation from being "epigenetic" and thus confused as some sort of Neo-lamarckian inheritance. The most extensive stuides in epigenomic variation and transgenerational inheritance have been done in plants. Much of these variants are genetic, not epigenetic, and its up in the air regarding those which no genetic basis have been determined.

 

I should also note that epigenetics is not limited to DNA. Prions are an incredible example of non-genetic inheritance that does not involve modification to DNA or its chromatin. Just one more reason why we should distinguish epigenetics from epigenomics.

 

Listen carefully to Alberto Perez, he actually makes this distinction. He referred to the markers as "epigenomic" not epigenetic. He then talks about specific instances of heritable examples, even though he never uses the term "epigenetic".

 

When you read press releases claiming something new about epigenetics, the environment, etc.; 9 times out of 10 its complete hype and crap.

Edited January 21, 2014 by chadn737