Which are the largest plant and animal virus?
The discovery of the Mimivirus in 2003 by Didier Raoult and Jean-Michel Claverie made headlines because of the virus remarkable size–comparable to that of many small bacteria. The pair’s new analysis of the Mimivirus genome reveals even more surprises. The DNA contains some 1260 genes, 50 of which code for functions never before seen in viruses, including DNA repair and translating mRNA into protein. Viruses are generally considered nonliving because of their small size, simplicity, and inability to replicate outside of a host cell. They’re just small packets of genetic material surrounded by a protein coating. But Claverie, a geneticist at Le Centre National de la Recherche Scientifique (CNRS) Structural and Genomic Information Laboratory in Marseille, France, believes that the Mimivirus’s complexity should make researchers rethink their characterization of viruses as nonliving. The Mimivirus may once have replicated on its own but later lost that ability, Claverie says. But the viru
