Arenavirus diversity and evolution: quasispecies in vivo.

Arenaviruses exist as viral quasispecies due to the high mutation rates of the low-fidelity viral RNA-dependent RNA polymerase (RdRp). This genomic heterogeneity is advantageous to the population, allowing for adaptation to rapidly changing environments that present varying types and degrees of selective pressure. The significant variation in biological properties observed among lymphocytic choriomeningitis virus (LCMV) strains, the prototypic arenavirus, indicates to what extent a quasis-pecies dynamics may play a role in arenavirus adaptability and pathogenesis. Several aspects of arenavirus variability and its contribution to pathogenesis will be discussed.