tailieunhanh - Báo cáo y học: "No observed effect of homologous recombination on influenza C virus evolution"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: No observed effect of homologous recombination on influenza C virus evolution | Han et al. Virology Journal 2010 TJ211 http content 7 1 227 VIROLOGY JOURNAL SHORT REPORT Open Access No observed effect of homologous recombination on influenza C virus evolution Guan-Zhu Han1 4 Maciej F Boni2 3 Si-Shen Li 1 Abstract The occurrence of homologous recombination in influenza viruses has been under some debate recently. To determine the extent of homologous recombination in influenza C virus recombination analyses of all available gene sequences of influenza C virus were carried out. No recombination signal was found. With the previous evidence in influenza A and B viruses it seems that homologous recombination has minimal or no effect on influenza virus evolution. Background The influenza C virus belongs to the Orthomyxoviridae family and is a common cause of mild upper respiratory tract illness. Seroepidemiological studies indicate that it is widely distributed around the world but isolated infrequently and the majority of humans acquire antibodies to the virus early in life 1 . In contrast with influenza A and B viruses the influenza C virus genome consists of only seven single stranded negative-sense RNA segments the PB2 PB1 P3 HE NP M and NS segments. Analysis of the full genome sequence of type C influenza viruses suggested that reassortment between two different type C influenza viruses occurs frequently in nature 2 3 . Furthermore influenza C virus has been suggested to be involved in heterologous RNA recombination events 4 . Largely because their RNA is always encapsidated by a ribonucleoprotein complex RNP single-stranded negative-sense RNA viruses are generally believed to undergo a low rate of homologous recombination 5 . However there is increasing evidence of homologous recombination involving negative-strand RNA viruses like Newcastle disease virus 5-8 Zaire Ebola virus 9 measles virus 10 and canine distemper virus 11 12 . Homologous recombination has also been demonstrated in the laboratory for respiratory syncytial .