Epigenetics

Epigenetics is the topic that is now engulfing the genetic community.  What is epigenetics?  Well, literally it means “above genetics”.  But the actual meaning is much more complicated than that.  Epigenetics is not necessarily your DNA, or even genes for that matter.  But it does however determine how much or whether certain genes are expressed.  In other words, what happens to you genes over the course of your life.  The really interesting thing is, what your grandparents did 50 years ago, can actually affect you today via your genes.  That’s right, habits your parents or grandparents had can actually be expressed in you.  And the same goes for your children, and grand children.  The core of epigenetics is the binding of methyl groups to the DNA.  This tells cells to express certain parts of your DNA in certain areas.  Histones, or the protein DNA is wrapped around also have an expression effect.  How the DNA strand is wound around these histones can effect gene expression.   The tighter a histone is wound, the less of that gene is expressed.  And the looser a gene is wound, the more that gene is expressed.  An analogy I like to use is methyl groups are like a switch, and histones are like a knob for genetic traits.  If your genome was a computer, DNA would be the hardware, and epigenetics would be more similar to the software.  Your DNA will never change; it is the same your whole life.  However, epigenetictags can be altered through out your life. 

That being said, epigenetic information is not permanent.  The “epigenome” changes most during periods of change in our bodies.  For example, puberty or pregnancy.  But it changes suddenly at all stages of our life.   What we put into our bodies and what we do can be huge factors on these epigenetic tags.  Only in the last 20 years have we really started to understand these epigenetic tags.  In the past we thought these epigenetic tags were stripped from DNA before reproduction.  However, while some are, we are learning that many are not.  This is where we come to talking about how your daily routine, can effect your unborn children.  This is thought to be some of the reason that traits like alcoholism and drug use are often genetic.  Or at least have genetically rated probability.  We first came across this trend when a public health specialist took a look at dietary trends from generation to generation in Sweden.  They found that those who grew up in an era of plentiful food died 6 years earlier than those who grew up in periods of scarcity.  Here is the scary part; their kids death patterns followed a similar trend.  And this is where the first thought of epigenetics occurred.  There is however a bright side in this.  We used to always think genes were the end all be all, meaning we could not escape how they unfolded.  However this is not true. Living a healthy life style can improve your genes and possibly even silence bad ones.  So just because you have a certain gene for something, does not necessarily mean it is expressed.