Viruses cause a large number of infectious diseases in human and veterinary medicine. Despite an extensive research effort, viral infections continue to appear in human and animal populations, as demonstrated by recent “new” viruses (HIV, SARS) and viral outbreaks can also have dramatic economical impact. Furthermore, emerging human viruses are often zoonotic infections. The advent of rapid and large-scale gene sequencing has allowed remarkable new into the viral evolution and molecular epidemiology of viral diseases. Viruses, especially those with RNA genomes, represent ideal organisms to study the dynamics of microevolutionary changes. RNA viruses have evolved a remarkable diversity of genomes and replicative mechanisms. Mutation rates during RNA virus replication are several orders of magnitude larger than those operating during replication of cellular DNA. This result in the continuous generation of mutant genomes and the dynamic mutant distributions that constitute RNA virus population are termed quasispecies. It is generally believed that the DNA virus genomes may be no more variable than cellular genes; but recent experimental data evidence multiple examples of genetic instability in the world of the DNA viruses. Phylogenetic analysis allows tracking the spread of virus strains, by investigating the genetic differences due to mutations that have accumulated over time. The strategies and mechanisms used by viruses in their evolutionary pathways and the tools used to investigate these processes are described.
Virus evolution and molecular epidemiology of viral diseases
BATTILANI, MARA
2009
Abstract
Viruses cause a large number of infectious diseases in human and veterinary medicine. Despite an extensive research effort, viral infections continue to appear in human and animal populations, as demonstrated by recent “new” viruses (HIV, SARS) and viral outbreaks can also have dramatic economical impact. Furthermore, emerging human viruses are often zoonotic infections. The advent of rapid and large-scale gene sequencing has allowed remarkable new into the viral evolution and molecular epidemiology of viral diseases. Viruses, especially those with RNA genomes, represent ideal organisms to study the dynamics of microevolutionary changes. RNA viruses have evolved a remarkable diversity of genomes and replicative mechanisms. Mutation rates during RNA virus replication are several orders of magnitude larger than those operating during replication of cellular DNA. This result in the continuous generation of mutant genomes and the dynamic mutant distributions that constitute RNA virus population are termed quasispecies. It is generally believed that the DNA virus genomes may be no more variable than cellular genes; but recent experimental data evidence multiple examples of genetic instability in the world of the DNA viruses. Phylogenetic analysis allows tracking the spread of virus strains, by investigating the genetic differences due to mutations that have accumulated over time. The strategies and mechanisms used by viruses in their evolutionary pathways and the tools used to investigate these processes are described.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
