It's all in our genes . . . or is it?

The publishing of the human genome project in 2003 was hailed as the dawn of a new age.

We finally understood everything that our genes encode for, we knew the secret of life, and with this new found knowledge we were going to eradicate diseases, famine, even old age?!

Unfortunately for the scientists working on the human genome things didn't so smoothly. It was all far too simple to account for the huge diversity of life.

As a human we all have a mother and father who each pass on their DNA to form our genome and this becomes the instruction manual for how we are built.

This genome forms the basis of Darwinian evolution - we are all stuck with the genes we got and depending on how successful our genes are we have more or less children who we pass our genes onto. However, just like any good building plans we need to have the ability to adapt. Thankfully we do.

Each gene in our genome is tightly controlled by various proteins generally known as transcription factors.

These transcription factors relay the signals each cell in our body gets and turns on or off genes as we need them.

Recently however some interesting findings have been made about our genes. In addition to being turned on or off as we need them they seem to be able to form a ‘memory' that can be passed down from parent to child which does not involve changes in our genome.

Various genes have been found that are either turned on or off regardless of whether transcription factors are present or not.

These genes have been chemically altered by having methyl groups added to them which rearranges the structure of our genome blocking these genes from being turned on.

One such gene is called the agouti viable yellow gene in mice. If this gene is switched on mice have a yellow coat however if the gene is methylated, it is switched off and mice have a sooty brown coat.

Different levels of methylation lead to a spectrum of mice coat colours even though all the mice have identical genomes.

This level of methylation can change throughout our life in response to a whole range of stimuli such as the amount of stress we are under, the amount of food we eat and whether we are exposed to diseases or not!

With these new found levels of complexity science has moved beyond the genome and the ‘Omics' revolution has begun where scientists map the transcriptome, proteome and physiome as well as many other networks which collectively make up the complexity of life!

Now just because something is coded for in our genes doesn't mean we have to spend the rest of our life living with it.

Mark Robinson, PhD Student, Department of Microbiology and Immunology.