Scientists Unlock Non-Coding Half of the Genome: The Mystery Behind 'Junk' DNA

Scientists may have just uncovered the secrets of an obscure swatch of human DNA that was once thought to be nothing more than biological trash. The new findings could shed light on complex genetic-related diseases, such as cancer and diabetes.

The piece of human DNA is called heterochromatin. This tightly packed section of the vast, non-coding section of the human genome was previously thought to have no real function and was considered to be "junk" DNA.

During the study, the researchers monitored the dynamics of the heterochromatic sequence in fruit flies by modifying a technique called quantitative polymerase chain reaction (QPCR), which is a process used to amplify specific DNA sequences from a relatively small amount of starting material. Then, they added fluorescent dye to see the fruit fly DNA changes and to observe any variations. In the end, the scientists found that differences in the heterochromatin exist. This, in particular, confirms that the junk DNA is not stagnant as researchers had originally believed. Instead, mutations that can affect other parts of the genome are capable of occurring.

"We know that there is hidden variation there, like disease proclivities or things that are evolutionarily important, but we never knew how to study it," said Keith Maggert, one of the researchers, in a news release. "We couldn't even do the simplest things because we didn't know if there was a little DNA or a lot of it. This work opens up the other non-coding half of the genome."

DNA material in chromosomes is made up of coding and non-coding regions. The coding regions, known as genes, contain the information necessary for a cell to make proteins. Yet far less is known about the non-coding regions, beyond the fact that they are not directly related to making proteins. Yet now, scientists have found a way to get a closer look at these non-coding sections.

"There is so much talk about understanding the connection between genetics and disease and finding personalized therapies," said Maggert. "However, this topic is incomplete unless biologists can look at the entire genome. We still can't-yet-but at least now we're a step closer."

The findings are published in the journal PLOS One.