Molecular evolution and emergence of avian gammacoronaviruses.

摘要: Coronaviruses, which are single stranded, positive sense RNA viruses, responsible for a wide variety of existing and emerging diseases in humans other animals. The gammacoronaviruses primarily infect avian hosts. Within this genus coronaviruses, the coronavirus infectious bronchitis virus (IBV) causes highly upper-respiratory tract disease commercial poultry. IBV shows rapid evolution chickens, frequently producing new antigenic types, adds to multiple serotypes that do not cross protect. Rapid is facilitated by strong selection, large population sizes high genetic diversity within hosts, transmission bottlenecks between Genetic host arises mutation, includes substitutions, insertions deletions. Mutations caused both error rate, limited proof reading capability, viral RNA-dependent RNA-polymerase, recombination. Recombination also generates haplotype recombining variants. makes extremely difficult diagnose control, but it an excellent model system study mechanisms behind emergence coronaviruses their natural host.