title: Pathogenicity of avian leukosis viruses related to fowl glioma-inducing virus.
abstract: Fowl glioma-inducing virus (FGV), which belongs to avian leukosis virus subgroup A, causes the so-called fowl glioma and cerebellar hypoplasia in chickens. In the present study, the complete nucleotide sequences of four isolates (Tym-43, U-1, Sp-40 and Sp-53) related to the FGV prototype were determined and their pathogenicity was investigated. Phylogenetic analysis showed that the 3'-long terminal repeat of all isolates grouped together in a cluster, while sequences of the surface (SU) proteins encoded by the env gene of these viruses had 85 to 96% identity with the corresponding region of FGV. The SU regions of Tym-43, U-1 and FGV grouped together in a cluster, but those of Sp-40 and Sp-53 formed a completely separate cluster. Next, C/O specific-pathogen-free chickens were inoculated in ovo with these isolates as well as the chimeric virus RCAS(A)-(FGVenvSU), constructed by substituting the SU region of FGV into the retroviral vector RCAS(A). The four variants induced fowl glioma and cerebellar hypoplasia and the birds inoculated with Sp-53 had the most severe lesions. In contrast, RCAS(A)-(FGVenvSU) provoked only mild non-suppurative inflammation. These results suggest that the ability to induce brain lesions similar to those of the FGV prototype is still preserved in these FGV variants.
authors.affiliation: Laboratory of Comparative Pathology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors.forename: Sayuri
authors.initials: S
authors.lastname: Nakamura
authors.forename: Kenji
authors.initials: K
authors.lastname: Ochiai
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hatai
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ochi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sunden
authors.forename: Takashi
authors.initials: T
authors.lastname: Umemura
mesh_terms: D000818:Animals; D001353:Avian Leukosis / Q000473:pathology / Q000821:virology*; D001354:Avian Leukosis Virus / Q000235:genetics* / Q000472:pathogenicity*; D001483:Base Sequence; D002645:Chickens; D016000:Cluster Analysis; D019295:Computational Biology; D017931:DNA Primers / Q000235:genetics; D005910:Glioma / Q000473:pathology / Q000821:virology*; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D010802:Phylogeny; D011201:Poultry Diseases / Q000473:pathology / Q000821:virology*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013047:Specific Pathogen-Free Organisms
chemical_list: D017931:DNA Primers