Molecular characterization of Sp110 gene in pigs.

Speckled 110 kDa (Sp110) plays an important role in infectious diseases, as revealed by studies in humans. However, little is known regarding porcine Sp110. To elucidate its potential role in porcine resistance to viral diseases, here, the complete coding sequence of porcine Sp110 gene and its 26 alternatively spliced isoforms were isolated using reverse transcription (RT)-polymerase chain reaction (PCR), and another seven splicing patterns were obtained using a minigene construct. Subcellular distribution of 11 representative isoforms was characterized in PK-15 cells transiently transfected with their respective GFP fusion constructs, and only isoforms (R and V) bearing all functional domains were localized in nucleus, indicating all the other isoforms lose normal functions of Sp110 owing to alternative splicing. Real-time quantitative PCR and competitive RT-PCR showed that both isoforms R and V had similar tissue expression profile, half-life and response to poly(I:C), a synthetic analog of viral double-stranded RNA, while the longer one (isoform R) was transcribed at a higher level. The results indicated that porcine Sp110 has a role in viral infection and that isoform R is the dominant active form. Overall the data provide potential resource for molecular breeding of pig resistant to diseases and contributes to breeding pigs resistant to viral infection.

Cloning and identification of splice variants of the porcine PILRA gene.

Paired immunoglobulin-like type 2 receptors (PILRs) are members of the immunoglobulin superfamily and composed of two subtypes, α and ß. PILRα plays an important role in the immune response against invading pathogens, but so far there is no report on porcine PILRα. In order to analyze the potential role of PILRα in porcine disease-resistant breeding, we first cloned the PILRA gene (V1-V3, GenBank accession Nos. KJ143679-81) into pigs, and identified its three splice variants. Each variant conceptually translates into proteins of 271 amino acids (aa), 254aa and 283aa, respectively. Furthermore, quantitative real-time PCR was used to construct expression profiles of each variant in tissues and that induced by Poly(I:C). All three variants had the highest expression levels in the spleen, followed by liver and lung tissues. While levels were low or undetectable in the heart, kidney, stomach, muscle, lymph, large intestine, small intestine and bladder. Poly(I:C) significantly induced the expression of splice variant 1 (V1) of porcine PILRA, but hardly affected the expression of V2 and V3. The results lay a foundation for further study on the role of PILRA in porcine breeding and disease resistance.