Epigenetics
When the human genome project
was completed many scientists thought that
genetic disease would become a thing of the
past; however, the geneticists did not find
answers only more problems. The issue is
that there are only thirty thousand genes in
humans. Original expectations were around
one hundred thousand and were as high as
two million. This was a massive shock and
signified that something was missing.
The solution to this problem was
found in twins. The expectation with
identical twins is that they are and always
will be exactly the same since they are
genetically identical, but cases have been
seen where one twin develops a disease such
as cancer or autism and another does not.
Much study has resulted in the conclusion
that the genetic code can be read in different
ways, meaning that parts of the code can be
blocked and others can be promoted.
Epigenetics is the study of
modifications that occur in DNA that cause
certain genes to be suppressed. The
mechanism for this is the bonding of many
methyl groups to the chromatin, preventing
RNA polymerase to read the code and create
a transcription. By blocking certain
segments of DNA cells can differentiate,
and create different tissues. Furthermore,
unlike the genome which is stable the
epigenome changes constantly. The
implications of this are huge, by
understanding how the epigenome behaves
therapies can be developed for once
incurable illnesses furthermore the
epigenome leaves a huge burden on humans,
since it is hereditary and is easily changed
by outside influences.
The epigenome plays a critical role
in gene suppression, a recent MIT study
found that 80 % of rats genetically
engineered to have a deficient methylating
enzyme died due to cancer. Further study
showed that humans as well as many other
animals contain genes that cause tumors as
well as one that prevent them, and as the
epigenome deteriorates over time risk of
expressing such genes or suppressing
necessary genes increas