title: Genetic diversity and phylogenetic analysis of glycoprotein GP85 of ALV-J isolates from Mainland China between 1999 and 2010: coexistence of two extremely different subgroups in layers.
abstract: Avian leukosis virus subgroup J (ALV-J), first isolated in 1989, preferentially infects meat-type birds. However, layer flocks in China have experienced outbreaks of this virus since 2008. To understand the genetic diversity of ALV-J in Chinese layers, we compared and analyzed the GP85 gene sequences of 106 ALV-J isolates that were isolated between 1999 and 2010 in Mainland China. The GP85 gene sequences of 41 layer isolates collected from 9 provinces of China between 2008 and 2010 belonged to two separate, highly diverse subgroups and were differentiated from meat-type chicken isolates. When compared to all meat-type isolates from China, Subgroup 1 exclusively contained current layer isolates and seemed to be dominant; all the isolates in this subgroup exhibited gene diversity, and many unique amino acid mutations were present. In contrast, the viruses in Subgroup 2 were perfectly conserved and shared high identity with the prototype meat-type chicken ALV-J strain HPRS-103. The two subgroups contained only two concurrent mutations at the same position. Moreover, most of the isolates in Subgroup 1 had two additional glycosylation sites (at positions 101 and 191) when compared with those in Subgroup 2. Our study provides evidence for the coexistence of two extremely different ALV-J subgroups in Chinese layers from 2008 to 2010, supporting the need for vaccine development and purification measures to prevent ALV-J infection in layers in China.
authors.affiliation: Division of Avian Infectious Diseases, National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China. panwei525@126.com
authors.forename: Wei
authors.initials: W
authors.lastname: Pan
authors.forename: Yulong
authors.initials: Y
authors.lastname: Gao
authors.forename: Litin
authors.initials: L
authors.lastname: Qin
authors.forename: Wei
authors.initials: W
authors.lastname: Ni
authors.forename: Zaisi
authors.initials: Z
authors.lastname: Liu
authors.forename: Binglin
authors.initials: B
authors.lastname: Yun
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiaole
authors.initials: X
authors.lastname: Qi
authors.forename: Honglei
authors.initials: H
authors.lastname: Gao
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001353:Avian Leukosis / Q000453:epidemiology / Q000821:virology*; D001354:Avian Leukosis Virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D002645:Chickens; D002681:China; D014644:Genetic Variation; D006023:Glycoproteins / Q000235:genetics; D008460:Meat / Q000821:virology; D008969:Molecular Sequence Data; D010802:Phylogeny; D011201:Poultry Diseases / Q000453:epidemiology / Q000821:virology*; D016415:Sequence Alignment
chemical_list: D006023:Glycoproteins