Researchers Identify Vital New Role for 'Junk' DNA

Ever since they were first discovered and dubbed “junk,” there has been debate among biologists whether the long, non-coding regions of the genome are, in fact, useless. Many have proposed that these sequences, which comprise a large majority of the overall genome, simply must have some reason to exist.

Now, biologists have an inkling as to what that reason might be. An international team based in Asia has published evidence that one particular chunk of the non-coding genome could be a vitally important moderator of cellular function.

Transposable elements are just one type of so-called “junk” in the genome, representing a large portion of the non-coding sequences. They originate from viral DNA, having been inserted as part of an infection that spread to fixation in entire species. This aggressive origin might seem to lend itself to the idea that the sequences could be useless, but they’ve also been around ...