AlaskaDenise
In Memoriam
November 4, 2010
RNA molecules aren’t always faithful reproductions of the genetic instructions contained within DNA, a new study shows. The finding seems to violate a tenet of genetics so fundamental that scientists call it the central dogma: DNA letters encode information, and RNA is made in DNA’s likeness. The RNA then serves as a template to build proteins.
But a study of RNA in white blood cells from 27 different people shows that, on average, each person has nearly 4,000 genes in which the RNA copies contain misspellings not found in DNA.
snip
RNA molecules contained misspellings at 20,000 different places in the genome, with about 10,000 different misspellings occurring in two or more of the people studied. The most common of the 12 different types of misspellings was when an A in the DNA was changed to G in the RNA. That change accounted for about a third of the misspellings.
snip
In order to rule out the virus, the researchers analyzed skin cells from the same people and found that RNA misspellings originally discovered in the white blood cells were also in the skin cells. And the misspellings aren’t just rare, random mistakes. “When DNA and RNA differ from each other it happens in nearly every RNA” copy, Li says.
The researchers don’t yet know how the RNA misspellings happen.
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The consequences of the misspellings are also unknown. For instance, misspellings might cause the RNA to be degraded faster or interfere with the molecule’s ability to make proteins.
Image: RNA polymerase II (large colored blob), an enzyme that transcribes DNA into messenger RNA (which specifies the order of amino acids in proteins)./NIGMS (hi-res)
http://www.wired.com/wiredscience/2010/11/rna-errors-genetics/
(The image on the original site is very good)
RNA molecules aren’t always faithful reproductions of the genetic instructions contained within DNA, a new study shows. The finding seems to violate a tenet of genetics so fundamental that scientists call it the central dogma: DNA letters encode information, and RNA is made in DNA’s likeness. The RNA then serves as a template to build proteins.
But a study of RNA in white blood cells from 27 different people shows that, on average, each person has nearly 4,000 genes in which the RNA copies contain misspellings not found in DNA.
snip
RNA molecules contained misspellings at 20,000 different places in the genome, with about 10,000 different misspellings occurring in two or more of the people studied. The most common of the 12 different types of misspellings was when an A in the DNA was changed to G in the RNA. That change accounted for about a third of the misspellings.
snip
In order to rule out the virus, the researchers analyzed skin cells from the same people and found that RNA misspellings originally discovered in the white blood cells were also in the skin cells. And the misspellings aren’t just rare, random mistakes. “When DNA and RNA differ from each other it happens in nearly every RNA” copy, Li says.
The researchers don’t yet know how the RNA misspellings happen.
snip
The consequences of the misspellings are also unknown. For instance, misspellings might cause the RNA to be degraded faster or interfere with the molecule’s ability to make proteins.
Image: RNA polymerase II (large colored blob), an enzyme that transcribes DNA into messenger RNA (which specifies the order of amino acids in proteins)./NIGMS (hi-res)
http://www.wired.com/wiredscience/2010/11/rna-errors-genetics/
(The image on the original site is very good)
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