Interrupted genes in extremophilic archaea: mechanisms of gene expression in early organisms.

Extremophilic Archaea populate biotopes previously considered inaccessible for life. This feature, and the possibility that they are the extant forms of life closest to the last common ancestor, make these organisms excellent candidates for the study of evolution on Earth and stimulate the exobiological research in planets previously considered totally inhospitable. Among the other aspects of the physiology of these organisms, the study of the molecular genetics of extremophilic Archaea can give hints on how the genetic information is transmitted and propagated in ancient forms of life. We review here the expression of interrupted genes in a recently discovered nanoarchaeon and the mechanisms of reprogrammed genetic decoding in Archaea.