When hundreds of scientists from around the world finally pieced together a draft of the first human genome in 2003, perhaps the biggest surprise was just how little of it was devoted to the business of producing proteins. About 98% of the genes in our chromosomes appeared not to do anything, earning the unflattering nickname “junk DNA.” But with better tools developed over the last 20 years, scientists began to discover that all that junk actually produces a diverse menagerie of RNA species transcribed and set loose to drift around the cell.
Figuring out exactly what each one does is the mission of an increasing number of researchers, including a team at MD Anderson Cancer Center in Texas. Years ago, they set out to determine the functions of one RNA species in particular — big ones, larger than 200 bases, known as long noncoding RNAs, or lncRNAs. Now, they’ve linked one of these RNA molecules to a discovery they say could aid in the development of new treatments for one of the most common genetic disorders, phenylketonuria.