By Keval Sheth

EPIGENETICS

What is Epigenetics?

• epigenetics is the study of inherited changes in phenotype (appearance) or gene expression

• Epigenetics means “above genetics.”

• There is very little background on epigenetics because it’s a very new field only about 50 years old!

• In the past we thought that a embryo's epigenome was completely erased and rebuilt from scratch. This is partially true, some of the epigenetic “tags” remain in place and therefore pass from generation to generation, this is called epigenetic inheritance.

Inheritance

• It means that a parent's experiences, in the form of epigenetic tags, can be passed down to future generations.

• An example is if you smoked your whole life then you're offspring (children) will have a higher chance of smoking

What does this mean?

• The epigenome is like the brain that tells you're cells what to become. Such as eye cells or muscle cells. It doesn’t change you're genes/DNA it just says what genes will be expressed

• The genome is like the muscle of the process it carriers out the orders from the Epigenome.

What is the Epigenome?

Methyl Group

• The methyl group tell you're genome what genes to express. The Methyl binds differently in a skin cell or a eye ball cell and that’s one of the ways a cell knows I'm a skin cell or I'm an eye ball cell.

Histones

• Histones also control epigenetics their like spools that wind the DNA up around them.

• The tighter there wound the less of the gene that is expressed or seen.

• Phosphorylation

• Acetylation

• Methylation-most common method

Three Techniques

Step 1 of Methylation

• Genome of interest is treated with sodium bisulfite.

• Un-methylated cytosine residues are converted to uracil, while methylated cytosine residues are unaffected.

Step 2

• PCR Amplification

• Bisulfite treated DNA is then PCR amplified, resulting in cytosine residues at originally methylated positions