Researchers in Boston figured that maybe they could find something interesting in all the non-protein, non-miRNA, non-siRNA genes. They did…linc-RNAs. Through a massive sequencing of ChIP data they uncovered a chromatin “signature” for actively transcribed regions between known protein coding genes, and used this signature to identify about 1700 previously un-annotated stretches of the genome at least five kb long.
Most of these, it turns out, are transcribed as multi-exonic RNAs (dubbed “large intervening non-coding RNA, or lincRNA), and most show sequence conservation of these linc-RNAs among mammals and evidence of genetic selection.
Examining lincRNA expression across developmental stage and cell type, and comparing it to mRNA expression, distinct sets of lincRNAs were associated with processes such as cell proliferation, morphogenesis, and immune surveillance. The lincRNAs, they found, are regulated by the same transcription factors as proteins involved in these same processes, indicating that they may likely function in concert. You won’t want to miss this one, so check it out online at Nature Biotechnology, February 2009.