By: Patrick Brown, 2nd year PhD candidate in the Biomedical Sciences Graduate Program
In Part I of my discussion of DNA and epigenetics, I described how DNA is first converted into mRNA via transcription, then mRNA is translated into protein. Once proteins are made from this genetic code, they can begin doing work in cells.
I ended the last article with the question: how does the body choose which genes are expressed in which cells? Here I will discuss the concept of epigenetics and its role in shaping protein expression.
We can see the effects of epigenetics all around us. Many proteins are expressed differently between males and females – these proteins are under epigenetic control. If epigenetic marks are abnormal, then certain cancers become more prevalent. The most visible difference in epigenetic marks is seen in the coat color of the agouti mouse. Each mouse pictured (above) is genetically identical, but contains different amounts of a specific epigenetic mark. How can they have the same genes, but have different coat colors?