“Don’t blame me. I got my meanness from your side of the
family.” …
“I got my stubbornness from Uncle Joe.” …
“I can’t help it; that’s just the way I am.”
“I got my stubbornness from Uncle Joe.” …
“I can’t help it; that’s just the way I am.”
Blaming your genes can make a
handy excuse. It is also highly misleading. A decade-long international
research collaboration involving 442 scientists in 32 worldwide institutions
now makes obsolete the original scientific views about DNA and genes. This
research initiative, called ENCODE, was initiated and largely funded by the
Genome Research Institute of the U.S. National Institutes of Health. Just this
week, some 30 groundbreaking publications have appeared in premier journals
such as Nature and Science.
This accumulated mountain of
data unequivocally demonstrates that most of our genes do not code for RNA that
translates into proteins used by the body. True, the ENCODE project confirmed
that there are about 21,000 traditional protein-coding genes, but they
constitute only about 3% of the human genome. Until now, all the other DNA was
thought to be “junk DNA,” presumably left over from ancient ancestors with no
function in today’s evolved species.
ENCODE scientists have
discovered that about 80% of the human genome does have function, but that DNA
transcribes RNA as end products that regulate
the expression of protein-coding genes. When a protein-coding gene is
expressed, its double helix strands of DNA become unzipped to expose the coding
nucleotides so they can translate the code into the RNA that will then
translate the code into the various proteins used by the body. Most of the DNA
previously thought to be “junk” has now been revealed to regulate gene
expression by way of enhancing or suppressing gene expression or shielding protein-coding
DNA.
Over 18,000 species of
regulatory RNA have been described. Clusters of regulatory genes are found
throughout the chromosomes, and they very often regulate non-adjacent genes,
often working with other regulatory genes as a team.
These new findings cause some
scientists to assert a need to redefine what a gene is. The basic unit of
heredity, they say, is not DNA, but rather its RNA transcripts. Why is this new
view important? Production of regulatory RNA is governed by the environment,
not your biological inheritance. These “epigenetic” influences include things
like what you eat, your bodily activities, what you think, and the feedback
from how you behave. For example, a muscle body builder, through intense
exercise, causes expression of genes to make extraordinary muscle mass. Think
Arnold Schwarzenegger before, during, and after his body building career. He
had the same protein coding genes all along, but their expression changed by
what he chose to do.
What this says is that you can control the expression of your
genes by the choices you make and by what you think and do. Most of us are born
with a genome that can generate a happy and productive life. Whether that
happens or not depends on how our choices and actions affect gene expression.
So, next time you are tempted
to blame your genes for a bad outcome, consider what role you played in the
expression of those genes. Science is showing the truth of Proverbs (chapter 23 verse 7),
“As a man thinks in his heart, so is he.”
Source:
Pennizi, Elizabeth (2012).
ENCODE project write eulogy for junk DNA. Science. 337: 1159-1161.
