Everyone wants to be judged based on their own merits, and not just what group they happen to be a part of. With the help of a talented crew from the University of Oxford, lncRNAs have just been given a wonderful holiday gift to help them break free of their one-size-fits-all stereotype; two distinct classes of lncRNAs.

In a recent publication that describes the new classifications, first author Ana Marques shares that “Previously, we knew many transcription and sequence-based properties of lncRNAs but hadn’t been able to tell apart different types of lncRNAs. With this manuscript we have taken a significant step towards lncRNA classification by separating two types – enhancer- or promoter-associated lncRNAs – and by showing that these types exhibit surprisingly different properties. LncRNA classification can now be based more on mechanism and function, rather than on length and genomic location” Here’s what the Oxford team discovered:

First they broke down the intergenic lncRNAs into two distinct classes, according to chromatin status at the lncRNAs transcriptional initiation site, which they categorized by levels of histone H3K4 mono- and trimethylation.

Applying their classification system, they found an almost equal abundance of two distinct types of lncRNAs: enhancer-associated (elncRNA) elements and promoter-associated (plncRNA) elements.

Marques and her team were somewhat surprised to discover that “…despite their transcription being associated with increased expression of protein-coding genes in their vicinity, elncRNAs evolved neutrally. This implies that either most elncRNAs, if functional, have species-specific roles, turning over very quickly during mammalian evolution, or that most elncRNAs have functions that do not require conservation of their underlying sequences.”

Marques also did not expect that “…half of all lncRNAs in this study originated at enhancers rather than canonical promoters and these differences in origin associate with functional properties, such as the correlation in expression of elncRNAs, but not plncRNAs, with neighboring protein-coding genes.

Marques concluded with her excitement that “… now we can begin to classify these enigmatic RNAs according to their function and evolution, rather than by more prosaic things such as length and genomic location.”

Learn about the latest about chromatin threads that lncRNAs are sporting over at Genome Biology, December 2013