Deletion of CD163 Exon 7 Confers Resistance to Highly Pathogenic Porcine Reproductive and Respiratory Viruses on Pigs.

Porcine reproductive and respiratory syndrome (PRRS) caused by PRRS virus (PRRSV) is a severe infectious disease in the swine industry. PRRSV infection is mediated by porcine CD163 (pCD163). Scavenger receptor cysteine-rich domain 5 coded by exon 7 of pCD163 is essential for PRRSV infection. In this study, we generated CD163 exon 7 deleted (CD163E7D) pigs using CRISPR/Cas9 mediated homologous recombination and somatic cell nuclear transfer (SCNT). The deletion of exon 7 had no adverse effects on CD163-associated functions. Pigs were further challenged with a highly pathogenic PRRSV (HP-PRRSV) strain. The CD163E7D pigs exhibited mild clinical symptoms and had decreased viral loads in blood. All CD163E7D pigs survived the viral challenge, while all the WT pigs displayed severe symptoms, and 2 out of 6 WT pigs died during the challenge. Our results demonstrated that CD163 exon 7 deletion confers resistance to HP-PRRSV infection without impairing the biological functions of CD163.

[Molecular cloning, expression profile analysis and construction of adipose tissue specific expression vector of pig Gli1 gene].

The Hedgehog (Hh) signaling pathway inhibits fat accumulation, which is conserved in a wide variety of organisms from Drosophila to vertebrates, but few reports about its effect on pigs are available. In this study, pig Gli1 gene was cloned for the first time by rapid amplification of cDNA ends (RACE) and RT-PCR. Pig Gli1 expression profiles were then studied in different tissues and in different developmental stages of the adipose tissue of pigs using real-time PCR. Finally, the eukaryotic expression vector and the adipose tissue specific expression vector were constructed. The results showed that the full pig Gli1 cDNA length was 3 576 bp, the genomic sequence contained 10 715 bp with 12 exons, and 1 106 amino acids were encoded. Pig Gli1 was predicted as an unstable hydrophilic protein without a tans-membrane structure or a signal peptide. The C2H2 zinc finger domain and a nuclear localization sequence were found in pig Gli1. A homology analysis of the Gli1 amino acids and the genomic sequences among seven species showed that the identities were all greater than 80%, which indicates that Gli1 is highly conserved among different species. Tissue expression profile analysis showed that pig Gli1 was only expressed in the tone tissue of adult pigs. Analysis of the pig adipose tissue developmental process showed that Gli1 was detected in the adipose tissue of one-week-old pigs, but not in one-month-old and three-month-old pigs. Finally, a pig Gli1 eukaryotic expression vector was constructed and properly expressed with cell transfection. An adipose tissue specific expression vector was constructed for transgenic animal studies.