I mentioned once before that Genome Technology Online is confused about non-coding DNA. Today they confirmed this: The Semantics of “Junk” DNA — We’re Confused, Too.

Greg Laden points out a recently published paper in PNAS that gives credence to the theory that non-coding RNA has specific function. The work identified 849 ncRNAs (of 1,328 examined) that are expressed in the adult mouse brain, the majority of which they also found were associated with and expressed in specific regions, cell types, or cellular compartments. He’s blasted here and here for his supposed naivety, but he maintains that the “paper is interesting and the evidence for ncRNA having some function is reasonable.”

Funny, that’s pretty much what I concluded about the paper too:

I am not about to claim that the study hasn’t shown evidence of function for these non-coding regions. I think it’s quite interesting, and it wouldn’t surprise me if lots of non-coding RNA turned out to have a regulatory function.

Greg wasn’t “blasted” by me, but I did point out his misinterpretation of the evidence for function in non-coding DNA, of which these non-coding RNAs are a tiny fraction. The extrapolation from this to “junk DNA” in general is what I was noting. I think aggregating services like Genome Technology Online are useful, but not when they do little more than give inaccurate comment.