title: Novel sequences of subgroup J avian leukosis viruses associated with hemangioma in Chinese layer hens.
abstract: BACKGROUND
  Avian leukosis virus subgroup J (ALV-J) preferentially induces myeloid leukosis (ML) in meat-type birds. Since 2008, many clinical cases of hemangioma rather than ML have frequently been reported in association with ALV-J infection in Chinese layer flocks.
  
  
  RESULTS
  Three ALV-J strains associated with hemangioma were isolated and their proviral genomic sequences were determined. The three isolates, JL093-1, SD09DP03 and HLJ09MDJ-1, were 7,670, 7,670, and 7,633 nt in length. Their gag and pol genes were well conserved, with identities of 94.5-98.6% and 97.1-99.5%, respectively, with other ALV-J strains at the amino acid level (aa), while the env genes of the three isolates shared a higher aa identity with the env genes of other hemangioma strains than with those of ML strains. Interestingly, two novel 19-bp insertions in the U3 region in the LTR and 5' UTR, most likely derived from other retroviruses, were found in all the three isolates, thereby separately introducing one E2BP binding site in the U3 region in the LTR and RNA polymerase II transcription factor IIB and core promoter motif ten elements in the 5' UTR. Meanwhile, two binding sites in the U3 LTRs of the three isolates for NFAP-1 and AIB REP1 were lost, and a 1-base deletion in the E element of the 3' UTR of JL093-1 and SD09DP03 introduced a binding site for c-Ets-1. In addition to the changes listed above, the rTM of the 3' UTR was deleted in each of the three isolates.
  
  
  CONCLUSIONS
  Our study is the first to discovery the coexistence of two novel insertions in the U3 region in the LTR and the 5' UTR of ALV-J associated with hemangioma symptoms, and the transcriptional regulatory elements introduced should be taken into consideration in the occurrence of hemangioma.
authors.affiliation: Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Pan
authors.forename: Yulong
authors.initials: Y
authors.lastname: Gao
authors.forename: Fenfen
authors.initials: F
authors.lastname: Sun
authors.forename: Litin
authors.initials: L
authors.lastname: Qin
authors.forename: Zaisi
authors.initials: Z
authors.lastname: Liu
authors.forename: Bingling
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: D020121:5' Untranslated Regions / Q000235:genetics; D000818:Animals; D001354:Avian Leukosis Virus / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity*; D002645:Chickens; D002681:China; D015686:Gene Products, env / Q000737:chemistry / Q000235:genetics; D016679:Genome, Viral / Q000235:genetics*; D006391:Hemangioma / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional / Q000235:genetics*; D011201:Poultry Diseases / Q000473:pathology* / Q000821:virology; D017422:Sequence Analysis, DNA; D020079:Terminal Repeat Sequences / Q000235:genetics
chemical_list: D020121:5' Untranslated Regions; D015686:Gene Products, env