title: A conserved African swine fever virus right variable region gene, l11L, is non-essential for growth in vitro and virulence in domestic swine.
abstract: The right variable region of the African swine fever virus (ASFV) genome is known to contain genes with functions involving virus virulence and host range in swine. A novel open reading frame, ORF l11L, which was absent in the non-pathogenic, cell culture-adapted European isolate BA71V, was identified in the pathogenic African isolate Malawi Lil-20/1. The location of l11L in the right variable region, together with its absence in BA71V, suggested that l11L may have a function in virus virulence and/or host range. Here, we show that the l11L gene is highly conserved among pathogenic African, European and Caribbean ASFV field isolates and that it exists either in a short form, encoding a protein of 77-78 amino acids (9.1 kDa) or in a longer form of 93-94 amino acids (11.1 kDa). The presence of two predicted membrane-spanning segments suggests that l11L is an integral membrane protein. RT-PCR analysis demonstrated that l11L mRNA is expressed late in the virus replication cycle. A recombinant l11L gene deletion mutant, deltal11L, was constructed from the ASFV isolate Malawi Lil-20/1 to examine gene function. Deletion of l11L did not affect virus replication in swine macrophage cell cultures nor virulence in domestic pigs, indicating that l11L is non-essential for growth in vitro and for virus virulence in domestic swine.
authors.affiliation: Plum Island Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Greenport, NY 11944-0848, USA.
authors.forename: S B
authors.initials: SB
authors.lastname: Kleiboeker
authors.forename: G F
authors.initials: GF
authors.lastname: Kutish
authors.forename: J G
authors.initials: JG
authors.lastname: Neilan
authors.forename: Z
authors.initials: Z
authors.lastname: Lu
authors.forename: L
authors.initials: L
authors.lastname: Zsak
authors.forename: D L
authors.initials: DL
authors.lastname: Rock
mesh_terms: D000358:African Swine Fever Virus / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification / Q000472:pathogenicity; D000595:Amino Acid Sequence; D000818:Animals; D000829:Animals, Domestic; D001483:Base Sequence; D002478:Cells, Cultured; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004279:DNA, Viral; D005814:Genes, Viral; D008264:Macrophages / Q000821:virology; D008969:Molecular Sequence Data; D011995:Recombination, Genetic; D017386:Sequence Homology, Amino Acid; D013552:Swine; D013987:Ticks; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000502:physiology*; D014774:Virulence
chemical_list: D004279:DNA, Viral; D014759:Viral Envelope Proteins