RT Journal Article SR Electronic(1) A1 Kleiboeker, S B A1 Kutish, G F A1 Neilan, J G A1 Lu, Z A1 Zsak, L A1 Rock, D LYR 1998 T1 A conserved African swine fever virus right variable region gene, l11L, is non-essential for growth in vitro and virulence in domestic swine. JF Journal of General Virology, VO 79 IS 5 SP 1189 OP 1195 DO https://doi.org/10.1099/0022-1317-79-5-1189 PB Microbiology Society, SN 1465-2099, AB 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., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-79-5-1189