All Roads Lead to the Lamprey

Research out of Dartmouth has linked miRNAs to the transition from invertebrate to vertebrate, according to a recent paper published in PNAS. The authors compared the miRNA expression patterns of lampreys, considered to be the first vertebrate, and non-vertebrate aquatic animals and found 41 families unique to lampreys. Wired quotes lead author Kevin Peterson as saying, "We're arguing that in the early ocean history of invertebrates, a stupendous amount of microRNAs evolved out of 'junk' DNA. Adding these regulators facilitated new cell types, and the new cell types made possible new structures and new complexity."