title: Competitive replication of different genotypes of infectious bursal disease virus on chicken embryo fibroblasts.
abstract: Infectious bursal disease virus (IBDV) causes immunosuppression in chickens. We investigated the molecular changes in chicken embryo fibroblasts (CEF) adapted IBDV by genomic sequencing. IBDV were serially passaged in CEF and chickens were infected with the IBDV obtained after different numbers of passages in CEF. Chicken infections showed that 16th, 20th, and 21st passage viruses were pathogenic, while 26th and 36th passage viruses were non-pathogenic. Sequencing demonstrated that the initial changes during the serial passage comprised of a single-nucleotide deletion in the 3' non-coding region of segment B of the virus after 19th passage, followed by changes in the VP1 gene after the 20th passage of the virus and changes in VP2, VP5 after the 21st passage of the virus. These data suggested that the attenuation of very virulent IBDV was due to multigenic mutations and there are in vitro and in vivo competitive replications in IBDV quasispecies.
authors.affiliation: Key Laboratory of Animal Epidemic Etiology and Immunological Prevention of Ministry of Agriculture, Zhejiang University, Hangzhou 310029, People's Republic of China.
authors.forename: Lixue
authors.initials: L
authors.lastname: Shi
authors.forename: Haibin
authors.initials: H
authors.lastname: Li
authors.forename: Guangpeng
authors.initials: G
authors.lastname: Ma
authors.forename: Jiyong
authors.initials: J
authors.lastname: Zhou
authors.forename: Lianlian
authors.initials: L
authors.lastname: Hong
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Zheng
authors.forename: Yongping
authors.initials: Y
authors.lastname: Wu
authors.forename: Yongzhi
authors.initials: Y
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
mesh_terms: D020413:3' Untranslated Regions; D000220:Adaptation, Biological; D000818:Animals; D001483:Base Sequence; D018175:Birnaviridae Infections / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D002478:Cells, Cultured; D002642:Chick Embryo; D002645:Chickens; D004252:DNA Mutational Analysis; D005347:Fibroblasts / Q000821:virology*; D005838:Genotype; D007243:Infectious bursal disease virus / Q000235:genetics / Q000472:pathogenicity*; D008969:Molecular Sequence Data; D011201:Poultry Diseases / Q000473:pathology* / Q000821:virology*; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D012692:Serial Passage; D014764:Viral Proteins / Q000235:genetics; D014774:Virulence; D014779:Virus Replication
chemical_list: D020413:3' Untranslated Regions; D012367:RNA, Viral; D014764:Viral Proteins