A joint effort between researchers at Lawrence Berkeley National Lab and the JGI showed in a study published yesterday at PLoS Biology that, despite contrary expectations, deleting portions of four ultraconserved regions in mice showed no change in phenotype. Since the discovery of ultraconserved elements in the human, mouse, and rat genomes, it's been assumed that these must confer an essential function. A blog post at Genomicron takes a look at the story of these genomic regions.
Meantime, GTO's paging David Haussler, king of ultraconserved elements, for some kind of explanation. Are we back to calling it junk DNA?