BACKGROUND: Viral genomic RNA-both single-stranded (ss) and double-stranded (ds)-is recognized by RNA-sensing Toll-like receptors (TLRs), notably TLR3 (dsRNA), TLR7 (ssRNA), and TLR8 (ssRNA). However, our knowledge of the roles of porcine TLR3, 7, and 8 in antiviral immunity is inadequate. METHODS: From information on exon-intron boundaries obtained through comparisons of the genomic and cDNA sequences, polymorphisms in the coding sequences of each gene were detected in 84 male pigs of 11 breeds. RESULTS: Genomic structures are conserved between pigs and humans. The RNA-sensing TLR genes had fewer polymorphisms causing amino acid alterations than did the cell-surface TLR genes, but the alterations were distributed with a similar bias toward ectodomains. CONCLUSIONS: The low level of diversity of substitutive polymorphisms in RNA-sensing TLRs than cell-surface ones implies that polymorphisms severely affecting function have been eliminated by selection pressure during longstanding pig breeding. GENERAL SIGNIFICANCE: Recognition of virus-derived RNA is critical in host defense against infection. These results should provide a useful clue to analysis of the association between polymorphisms in RNA-sensing TLRs and disease resistance.
BACKGROUND: Viral genomic RNA-both single-stranded (ss) and double-stranded (ds)-is recognized by RNA-sensing Toll-like receptors (TLRs), notably TLR3 (dsRNA), TLR7 (ssRNA), and TLR8 (ssRNA). However, our knowledge of the roles of porcine TLR3, 7, and 8 in antiviral immunity is inadequate. METHODS: From information on exon-intron boundaries obtained through comparisons of the genomic and cDNA sequences, polymorphisms in the coding sequences of each gene were detected in 84 male pigs of 11 breeds. RESULTS: Genomic structures are conserved between pigs and humans. The RNA-sensing TLR genes had fewer polymorphisms causing amino acid alterations than did the cell-surface TLR genes, but the alterations were distributed with a similar bias toward ectodomains. CONCLUSIONS: The low level of diversity of substitutive polymorphisms in RNA-sensing TLRs than cell-surface ones implies that polymorphisms severely affecting function have been eliminated by selection pressure during longstanding pig breeding. GENERAL SIGNIFICANCE: Recognition of virus-derived RNA is critical in host defense against infection. These results should provide a useful clue to analysis of the association between polymorphisms in RNA-sensing TLRs and disease resistance.
Authors: Kwame A Darfour-Oduro; Hendrik-Jan Megens; Alfred Roca; Martien A M Groenen; Lawrence B Schook Journal: Immunogenetics Date: 2015-12-23 Impact factor: 2.846
Authors: Ronan Kapetanovic; Lynsey Fairbairn; Alison Downing; Dario Beraldi; David P Sester; Tom C Freeman; Christopher K Tuggle; Alan L Archibald; David A Hume Journal: BMC Genomics Date: 2013-08-28 Impact factor: 3.969