Each person has one genome but multiple epigenomes, depending on the cell type

What you experience in your lifetime can modify your DNA, and these changes can be passed down through the generations


Excerpt: "Everyone's heard of the genome: that double helix DNA code that is uniquely yours, unless you happen to have an identical twin. But there's another layer of complexity responsible for creating us — and that's the epigenome.

While every one of us has one unique DNA code, we all have many epigenomes because every different type of cell in the body — in your skin, fat, liver, and brain — has its own epigenome.

The science of epigenetics is just getting started, but promises to deliver big changes to the way we treat disease and understand heredity.

How can our lifestyles change our epigenome?

Epigenetic changes occur throughout our lives, in fact a degree of adaptability seems to be required for normal human health.

We know that smoking, alcohol consumption, diet, physical activity, obesity, psychological stress, trauma, physical stress, infectious diseases, environmental pollutants, sun exposure, working night shift and countless other environmental factors can change our epigenomes. We just don't know a lot of the details about how and to what extent.

"It's complicated, and we've only really in the last five years had the tools to be able to address the epigenome," said Professor Susan Clark, Head of Genomics and Epigenetics at the Garvan Institute of Medical Research.

Research into epigenetics is in its early days and understanding the impact of lifestyle factors on an individual's epigenome and health is tricky, mostly because it's difficult to run studies on humans for ethical reasons.

How are epigenetic changes passed on?

One of the most interesting and controversial aspects of epigenetics is the concept of inheritance. This suggests that events in our lives can affect our children's development and health, and possibly our grandchildren's.

Similarly, experiences our parents and grandparents had before we were born may also impact on our lives.

And until we know more, following a healthy lifestyle and doing the things we know have a positive impact on your health — such as eating a good diet, avoiding alcohol, doing exercise; and keeping stress to a minimum — is a good idea."

My comment: An addition or removal of only one methyl group on a cytosine base or a histone might have a big impact on protein synthesis. Correctly placed methyl groups are essential for successful cell differentiation. There are not so many types of epigenetic markers used on the DNA but modern science is aware of over one hundred epigenetic markers used in RNA. Short and long non-coding RNA-molecules also belong to epigenetic mechanisms. The number of long non-coding RNA-molecules is huge: 27,919 (March 2017). Scientists have not yet mapped for all short non-coding RNA-molecules, but the number will be much bigger than so-called human protein coding genes, 19,600.

Human traits are determined by epigenetic factors. Epigenetic information layers have also a strong association with genetic bases. Aberrant or disrupted methylation patterns can trigger genetic mutations that cause faulty genes and loss of biological information. That's why it's important to take care of your epigenome. And we remember that epigenetic modifications are inheritable by different ways and levels of stability. For example, histone modifications can be passed on for at least 14 generations.

These complex mechanisms point to creation and design. Don't get lost.