[Paleopsych] BH: Deleting Junk DNA Does No Harm
shovland at mindspring.com
Thu Oct 21 21:21:44 UTC 2004
Not presently used?
In making CD's, studios sample frequencies
far higher than what people can hear because
it affects the sound.
Perhaps the "junk" DNA represents subroutines
that are called when needed.
From: Premise Checker [SMTP:checker at panix.com]
Sent: Thursday, October 21, 2004 1:30 PM
To: paleopsych at paleopsych.org
Subject: [Paleopsych] BH: Deleting Junk DNA Does No Harm
Deleting Junk DNA Does No Harm
Mouse experiment reinforces theory that large chunks of the human genome
serve no function
By Liz Brown
10/20/2004 3:38 PM
Process of elimination: Deleting large chunks of DNA in mice does them
no harm, supporting the theory that the human genome contains lots of
Large segments of our DNA may have absolutely no function and could
apparently be removed without ill effect.
At least, this is what researchers from the US Department of Energy
Joint Genome Institute (JGI) and Lawrence Berkeley National
Laboratory in Berkeley, California discovered when they deleted large
parts of DNA sequences shared by mice and humans in lab mice.
The researchers set out to discover what function--if any--noncoding
DNA had. When the human DNA sequence was mapped, scientists found that
98% of the genome appeared to contain no genes.
"In these studies, we were looking particularly for sequences that
might not be essential," says Eddy Rubin, director of the JGI. "We
were surprised, given the magnitude of that information being deleted
from the genome, by the complete lack of impact noted."
Removing the walls
The researchers began eliminating sections of mouse DNA to determine
if the noncoding sections had any function. "To use an architectural
analogy, we asked which walls in the room actually support the ceiling
above," says Marcelo Nbrega, lead author of the study. "Remove the
walls and you will know."
Genetically engineering embryonic cells and then creating mice from
these cells, the researchers deleted 2.3 million letters of DNA code
from the 2.7 billion-base-pair mouse genome.
When the researchers compared the genetically altered mice with normal
mice, they could detect no differences in any areas, including
viability, growth and longevity.
"By and large, these deletions were tolerated and didn't result in any
noticeable changes," says Nbrega. "An important caveat, however, is
that no matter how detailed our analyses, our ability to test for a
particular characteristic in mice is limited. All we know is that, in
the time frame examined, there were no detectable changes in the
specific features that we studied."
The mouse genome is about 14% smaller than the human genome, but is
surprisingly similar in its sequence. This means it is likely that
eliminating these same areas in human DNA wouldn't have an effect on
the human body, a finding that provides a better understanding of our
The research is reported in the journal Nature (read abstract).
paleopsych mailing list
paleopsych at paleopsych.org
More information about the paleopsych