Researchers look into components of RNA silencing machinery
"Understanding normal chromosome biology is more than a curious scientific endeavor," says Aramayo. "It is a must if we ever are to conquer disease."
Up to 95 percent of a person's DNA is believed to be junk DNA. In order to prevent these relics of evolution from rearranging chromosomes and causing disease, natural mechanisms exist to silence them, according to contemporary theories of chromosome biology.
The RNA silencing machinery silences gene expression, by destroying RNA, a molecule that carries out DNA's instructions. Two years ago, components of the RNA silencing machinery were shown to be absolutely required for forming heterochromatin, a chromatin state that silences DNA, suggesting a new rule in biology. But researchers from Texas A&M University and the University of Oregon disagree.
They broke that rule in reporting their findings in the current issue of Science magazine. Funding for the research is supported by grants from the National Institutes of Health.
In a study with Neurospora crassa, a mold, Aramayo and his colleagues created mutant cells that cannot produce any key components of the RNA silencing mechanism, and discovered that heterochromatin formed just fine.
"What we have shown," Aramayo says, "is that cells have evolved more than one way to do the same thing. And this is important, because similar mechanisms might be present in human cells."
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