title: Sequence and expression analyses of porcine ISG15 and ISG43 genes.
abstract: The coding sequences of porcine interferon-stimulated gene 15 (ISG15) and the interferon-stimulated gene (ISG43) were cloned from swine spleen mRNA. The amino acid sequences deduced from porcine ISG15 and ISG43 genes coding sequence shared 24-75% and 29-83% similarity with ISG15s and ISG43s from other vertebrates, respectively. Structural analyses revealed that porcine ISG15 comprises two ubiquitin homologues motifs (UBQ) domain and a conserved C-terminal LRLRGG conjugating motif. Porcine ISG43 contains an ubiquitin-processing proteases-like domain. Phylogenetic analyses showed that porcine ISG15 and ISG43 were mostly related to rat ISG15 and cattle ISG43, respectively. Using quantitative real-time PCR assay, significant increased expression levels of porcine ISG15 and ISG43 genes were detected in porcine kidney endothelial cells (PK15) cells treated with poly I:C. We also observed the enhanced mRNA expression of three members of dsRNA pattern-recognition receptors (PRR), TLR3, DDX58 and IFIH1, which have been reported to act as critical receptors in inducing the mRNA expression of ISG15 and ISG43 genes. However, we did not detect any induced mRNA expression of IFNalpha and IFNbeta, suggesting that transcriptional activations of ISG15 and ISG43 were mediated through IFN-independent signaling pathway in the poly I:C treated PK15 cells. Association analyses in a Landrace pig population revealed that ISG15 c.347T>C (BstUI) polymorphism and the ISG43 c.953T>G (BccI) polymorphism were significantly associated with hematological parameters and immune-related traits.
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education and Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, Hubei, PR China.
authors.forename: Jiangnan
authors.initials: J
authors.lastname: Huang
authors.forename: Shuhong
authors.initials: S
authors.lastname: Zhao
authors.forename: Mengjin
authors.initials: M
authors.lastname: Zhu
authors.forename: Zhenfang
authors.initials: Z
authors.lastname: Wu
authors.forename: Mei
authors.initials: M
authors.lastname: Yu