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Their findings, published recently in the journal eLife, indicate that this genetic "junk" performs the vital function of ensuring that chromosomes bundle correctly inside the cell's nucleus, which is necessary for cell survival. And this function appears to be conserved across many species.
This pericentromeric satellite DNA consists of a very simple, highly repetitive sequence of genetic code. Although it accounts for a substantial portion of our genome, satellite DNA does not contain instructions for making any specific proteins. What's more, its repetitive nature is thought to make the genome less stable and more susceptible to damage or disease. Until fairly recently, scientists believed this so-called "junk" or "selfish" DNA did not serve any real purpose.
"But we were not quite convinced by the idea that this is just genomic junk," said Yukiko Yamashita, research professor at the LSI and lead author on the study. "If we don't actively need it, and if not having it would give us an advantage, then evolution probably would have gotten rid of it. But that hasn't happened."
Yamashita and her colleagues decided to see what would happen if cells could not use this pericentromeric satellite DNA. Because it exists in long, repetitive sequences, the researchers could not simply mutate or cut the entire satellite DNA out of the genome. Instead, they approached the question through D1, a protein known to bind to satellite DNA.
Comment: See:
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Also check out SOTT radio's: Behind the Headlines: Earth changes in an electric universe: Is climate change really man-made?