title: Growth and virulence alterations of equine herpesvirus 1 by insertion of a green fluorescent protein gene in the intergenic region between ORFs 62 and 63.
abstract: Nucleotide sequences of the intergenic region between ORF 62 and ORF 63 of equine herpesvirus 1 (EHV-1) isolates were analyzed. The sequences of this region consisted of variable and conserved domains among EHV-1 isolates. An EHV-1 mutant, Ab4-GFP, was constructed by inserting a green fluorescent protein (GFP) expression cassette flanked by lox P at both ends into the intergenic region between ORF 62 and ORF 63. Another mutant, Ab4-loxP, which contains one lox P site, was constructed by excision of the GFP cassette from the Ab4-GFP virus genome by cre enzyme. The recombinant Ab4-GFP formed smaller plaques than the wild type in MDBK cells. Virus production also decreased for Ab4-GFP in multistep growth analyses. Virulence of Ab4-GFP in both mice and hamsters was weaker than that of the wild type. Ab4-loxP exhibited properties similar to those of the wild type. These results suggest that the intergenic region between ORF 62 and ORF 63 plays various roles in the virus growth.
authors.affiliation: Department of Applied Veterinary Sciences, United Graduate School of Veterinary Sciences, Gifu University, Japan.
authors.forename: El Sayed Moustafa
authors.initials: el SM
authors.lastname: Ibrahim
authors.forename: Ochir
authors.initials: O
authors.lastname: Pagmajav
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Tomio
authors.initials: T
authors.lastname: Matsumura
authors.forename: Hideto
authors.initials: H
authors.lastname: Fukushi
mesh_terms: D000818:Animals; D002417:Cattle; D002460:Cell Line; D006224:Cricetinae; D021901:DNA, Intergenic / Q000235:genetics*; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics* / Q000378:metabolism; D006566:Herpesviridae Infections / Q000503:physiopathology / Q000821:virology; D004861:Herpesvirus 1, Equid / Q000235:genetics / Q000254:growth & development* / Q000472:pathogenicity*; D006734:Horse Diseases / Q000821:virology; D006736:Horses; D051379:Mice; D008807:Mice, Inbred BALB C; D016366:Open Reading Frames / Q000235:genetics*; D011995:Recombination, Genetic; D010948:Viral Plaque Assay; D014764:Viral Proteins / Q000235:genetics; D014774:Virulence
chemical_list: D021901:DNA, Intergenic; D014764:Viral Proteins; D049452:Green Fluorescent Proteins