Molecular evolution of the fusion protein gene in human respiratory syncytial virus subgroup A

作者：Kimura Hirokazu^*; Nagasawa Koo; Tsukagoshi Hiroyuki; Matsushima Yuki; Fujita Kiyotaka; Yoshida Lay Myint; Tanaka Ryota; Ishii Haruyuki; Shimojo Naoki; Kuroda Makoto; Ryo Akihide

来源：Infection, Genetics and Evolution, 2016, 43: 398-406.

DOI：10.1016/j.meegid.2016.06.019

• HRSV
• F gene
• Molecular evolution
• Palivizumab

We studied the molecular evolution of the fusion protein (F) gene in the human respiratory syncytial virus subgroup A (HRSV-A). We performed time-scaled phylogenetic analyses using the Bayesian Markov chain Monte Carlo (MCMC) method. We also conducted genetic distance (p-distance), positive/negative selection, and Bayesian skyline plot analyses. Furthermore, we mapped the amino acid substitutions of the protein. The MCMC-constructed tree indicated that the HRSV F gene diverged from the bovine RSV (BRSV) gene approximately 550 years ago and had a relatively lowsubstitution rate (7.59 x 10(-4) substitutions/site/year). Moreover, a common ancestor of HRSV-A and -B diverged approximately 280 years ago, which has since formed four distinct clusters. The present HRSV-A strains were assigned six genotypes based on F gene sequences and attachment glycoprotein gene sequences. The present strains exhibited high F gene sequence similarity values and low genetic divergence. No positive selection sites were identified; however, 50 negative selection sites were identified. F protein amino acid substitutions at 17 sites were distributed in the F protein. The effective population size of the gene has remained relatively constant, but the population size of the prevalent genotype (GA2) has increased in the last 10 years. These results suggest that the HRSV-A F gene has evolved independently and formed some genotypes.

• 出版日期2016-9