title: Evolution and homologous recombination of the hemagglutinin-esterase gene sequences from porcine torovirus.
abstract: The objective of the present study was to gain new insights into the evolution, homologous recombination, and selection pressures imposed on the porcine torovirus (PToV), by examining the changes in the hemagglutinin-esterase (HE) gene. The most recent common ancestor of PToV was estimated to have emerged 62 years ago based upon HE gene sequence data obtained from PToV isolates originating from Spain, South Korea, Netherlands, Hungary, and Italy and using the HE gene of Bovine torovirus isolates Niigata1 (AB661456) and Niigata3 (AB661458) as outgroups. The HE gene sequence data segregated all the PToV isolates into two well-supported monophyletic groups; however, various isolates from Spain, Italy, and South Korea did not segregate geographically suggesting very recent translocation of the viruses to these localities. Evidence of recombination was observed between two South Korean isolates that partitioned into two distinct subclades. Data further suggest that most of the nucleotides in the HE gene are under negative selection; however, changes within codon 237 showed an evidence of positive selection.
authors.affiliation: College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin 150030, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Cong
authors.forename: Dante S
authors.initials: DS
authors.lastname: Zarlenga
authors.forename: Juergen A
authors.initials: JA
authors.lastname: Richt
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Siqingaowa
authors.initials: S
authors.lastname: Suo
authors.forename: Jingfei
authors.initials: J
authors.lastname: Wang
authors.forename: Yudong
authors.initials: Y
authors.lastname: Ren
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Ren
mesh_terms: D000818:Animals; D001483:Base Sequence; D019143:Evolution, Molecular; D006389:Hemagglutinins, Viral / Q000737:chemistry / Q000235:genetics*; D059765:Homologous Recombination; D007558:Italy; D008969:Molecular Sequence Data; D009426:Netherlands; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D056910:Republic of Korea; D012641:Selection, Genetic; D013030:Spain; D013552:Swine; D013553:Swine Diseases / Q000821:virology*; D017003:Torovirus / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D018176:Torovirus Infections / Q000662:veterinary* / Q000821:virology; D014760:Viral Fusion Proteins / Q000737:chemistry / Q000235:genetics*
chemical_list: D006389:Hemagglutinins, Viral; D014760:Viral Fusion Proteins; C060814:hemagglutinin esterase