Functional and evolutionary analysis of host Synaptogyrin-2 in porcine circovirus type 2 susceptibility

In this study, CRISPR/Cas9-mediated gene editing of the porcine kidney 15 (PK15,wtSYNGR2+p.63Arg) cell line generated clones homozygous for the favorableSYNGR2 p.63Cys allele (emSYNGR2+p.63Cys). Infection of edited clones resulted in decreased PCV2 replication compared to wildtype PK15 (P700) revealed the favorableSYNGR2 p.63Cys allele is unique to domestic pigs and more predominant in European than Asian breeds. A haplotype defined by theSYNGR2 p.63Cys allele was likely derived from an ancestral haplotype nearly fixed within European (0.977) but absent from Asian wild boar. We hypothesize that theSYNGR2 p.63Cys allele arose post-domestication in ancestral European swine. Decreased genetic diversity in homozygotes for theSYNGR2 p.63Cys allele compared toSYNGR2 p.63Arg, corroborates a rapid increase in frequency ofSYGNR2 p.63Cys via positive selection. Signatures of adaptive evolution across mammalian species were also identified withinSYNGR2 intraluminal loop domains, coinciding with the location ofSYNGR2 p.Arg63Cys. Therefore,SYNGR2 may reflect a novel component of the host-virus evolutionary arms race across mammals withSYNGR2 p.Arg63Cys representing a species-specific example of putative adaptive evolution.
Source: PLoS Genetics - Category: Genetics & Stem Cells Authors: Source Type: research