Old questions, new answers

A virus has provided a hint of how the Earth's first organisms got things done. Many biologists believe that the earliest forms of life comprised molecules of ribonucleic acid (RNA) - DNA's chemical cousin - that were able to copy themselves. Now Steven Lommel, a virologist at North Carolina State University in Raleigh, USA, suggests how these early RNAs themselves might have regulated that copying. His team reports the discovery of a present-day virus that still employs a similar type of regulation. Lommel and his fellow researchers discovered that a tiny snippet of RNA in the red clover nectric mosaic virus directly turns on a gene for making the virus's protein casing (Science, Vol 281, p829). Normally, proteins turn genes on and off. However, the virus is still modern compared to the theoretical early life forms - it needs an enzyme to copy its RNA.