Where does Genomic `Dark Matter` originate from?

Scientists at Penn State University understood the origins of genomic “dark matter”. This forms over 95% of the human genome and doesn`t contain the blueprint to make proteins. This discovery might help to identify where complex-disease traits reside. The research was performed by B. Franklin Pugh, holder of the Willaman chair in Molecular Biology at Penn State, and postdoctoral scholar Bryan Venters, who is holding a faculty position at Vanderbilt University. “During transcription, DNA is copied into RNA – the single-stranded genetic material that is thought to have preceded the appearance of DNA on Earth – by an enzyme called RNA polymerase and, after several more steps, genes are encoded and proteins eventually are produced”, Pugh explained. “We took this approach because so many RNAs are rapidly destroyed soon after they are made, and this makes them hard to detect”, Pugh said. “So rather than look for the RNA product of transcription we looked for the `initiation machine` that makes the RNA. This machine assembles RNA polymerase, which goes on to make RNA, which goes on to make a protein”. “This finding is even more remarkable, given that fewer than 10,000 of these machines actually were found right at the sight of genes. Since most genes are turned off in cells, it is understandable why they are typically devoid of the initiation machinery”. “These non-coding RNAs have been called the `dark matter` of the genome because, just like the dark matter of the universe, they are massive in terms of coverage – making up over 95 percent of the human genome. However, they are difficult to detect and no one knows exactly what they are all doing or why they are there”, Pugh said. Pugh admits that this research could be one step ahead in solving the problem of “missing heritability”.