title: The Asia 2 specific signal peptide region and other domains in fusion protein genes characterized Asia 1 and Asia 2 canine distemper viruses.
abstract: BACKGROUND
  Although the presence of Asia 2 group of canine distemper virus (CDV) was known by the sequencing and phylogenetic analysis of hemagglutinin (H) gene, the fusion (F) protein gene sequence of Asia 2 group had not been identified. So, the sequence analysis of F gene was carried out to elucidate the genotypic varaitons among Asian isolates.
  
  
  RESULTS
  The phylogenetic analysis of F and H gene sequences from fourteen CDV isolates obtained from diseased dogs in Japan and Thailand indicated that the F genes had a new initiation codon and extra 27 nucleotides upstream of the usual open reading frame (ORF) and the F proteins had extra 9 amino acids at the N-terminal position only in Asia 2 isolates. On the contrary, the Asia 1 isolates had three extra putative N-glycosylation sites (two sites in the signal peptide region and one site in the F1 region) except for two strains of Th12 and Ac96I (two sites in signal peptide region) adding to four putative N-glycosylation sites that were conserved among all Asian isolates and Onderstepoort strain. In addition to this difference in N-glycosylation sites, the signal peptide region had a great diversity between Asia 1 and Asia 2 isolates. Also, characteristic amino acids were detected for some strains.
  
  
  CONCLUSIONS
  Asia 2 isolates were distinguished from other CDV lineages by the extra 27 nucleotide sequence. The signal peptide region of F gene gives a remarkable differentiation between Asia 1 and Asia 2 isolates. Strains Th12 and Ac96I were differentiated from other Asia 1 strains by the F protein glycosylation sites.
authors.affiliation: Department of Veterinary Microbiology, Faculty of Agriculture, Yamaguchi University, Yamaguchi, Japan. seaas@lycos.com
authors.forename: Serageldeen
authors.initials: S
authors.lastname: Sultan
authors.forename: Nataya
authors.initials: N
authors.lastname: Charoenvisal
authors.forename: Nguyen Thi
authors.initials: NT
authors.lastname: Lan
authors.forename: Ryoji
authors.initials: R
authors.lastname: Yamaguchi
authors.forename: Ken
authors.initials: K
authors.lastname: Maeda
authors.forename: Kazushige
authors.initials: K
authors.lastname: Kai
mesh_terms: D000818:Animals; D001208:Asia; D016000:Cluster Analysis; D004216:Distemper / Q000821:virology*; D004217:Distemper Virus, Canine / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D004285:Dogs; D014644:Genetic Variation; D006389:Hemagglutinins, Viral / Q000235:genetics; D007564:Japan; D016254:Mutagenesis, Insertional; D010802:Phylogeny; D021382:Protein Sorting Signals / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013785:Thailand; D014760:Viral Fusion Proteins / Q000235:genetics*
chemical_list: D006389:Hemagglutinins, Viral; D021382:Protein Sorting Signals; D014760:Viral Fusion Proteins; C076619:F protein, Phocine distemper virus