Our DNA contains long stretches of stuff that, because it didn’t immediately have a use, was originally classified as “junk”. This so-called junk DNA was thought to just sort of hold together the useful bits.
Over the years, more and more scientists have started finding gems in that junk. Now, Daniel Lim at UCSF and MD/PhD student Alexander Ramos have discovered that some of the junk is responsible for guiding how our brains develop. Specifically, Ramos, who has a training grant from CIRM, looked at long RNA molecules that are coded for by the junk DNA.
(A quick refresher: genes in our DNA code for RNAs that act as a template for creating proteins. These are the proteins that carry out all the cellular functions like making energy, producing hair or churning out hormones.)
The long RNAs that Ramos examined don’t actually create proteins and were as mysterious as the junk DNA from which they arose.
Ramos found more than 2,000 of these so-called lncRNAs in a group of neurons in the brain. He then crunched those sequences through a computer program that would compare them with types of brain diseases like Huntington’s disease and Alzheimer’s disease. So far, he found associations between 88 of those sequences and the development of Huntington’s disease, and he found some weaker associations between some lncRNAs and Alzheimer’s disease, seizures, depressive disorders and forms of cancer. They published this work in the April 11 online issue of Cell Stem Cell.
What these results mean is still a bit of a mystery, though where there are associations with disease there is the possibility of new avenues for developing therapies. That’s where other researchers come in. In a press release from UCSF Ramos said,
“There’s enough here for several labs to work on. It should be of interest to scientists who study long noncoding RNA, the generation of new nerve cells in the adult brain, neural stem cells and brain development, and embryonic stem cells.”They’ve created a website where other researchers can download the data and analyze it for themselves.