Isolation, molecular cloning, and characterization of a novel porcine lymphotoxin beta receptor gene.

The lymphotoxin beta receptor (LTβR) is a member of the tumor necrosis factor family of receptors (TNFR). It plays a role in regulating lymphoid organogenesis and homeostasis of the immune system. In the present study, the full coding region of a putative LTβR gene of Sus scrofa was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and cloned for the first time (accession Nos. JX457347 and AFU74012). In addition, analysis of the tissue expression profile was carried out via RT-PCR. The full-length coding region of porcine LTβR had 1266 nucleotides (molecular weight, 45.61 kDa; pI, 5.71) and encoded 421 amino acids. Bioinformatic prediction indicates that LTβR belongs to the TNFR superfamily and contains a TNFR domain. The sequence homology analysis revealed that the amino acid sequences of S. scrofa LTβR had 82.9, 82.4, 81.3, 80.5, 78.7, 74.6, and 73.0% identity with those of Equus caballus, Canis lupus, Ailuropoda melanoleuca, Oryctolagus cuniculus, Bos taurus, Mus musculus, and Homo sapiens, respectively. The phylogenetic tree based on the amino acid sequences of LTβR from 8 species revealed that S. scrofa was more closely related to E. caballus, C. lupus, and A. melanoleuca. RT-PCR analysis showed that the porcine LTβR gene was differentially expressed (e.g., high, moderate, low, or nonexistent) in various tissues (e.g., prostate, pituitary, brainstem, and esophagus, respectively). This may be related to differences in the regulation of LTβR in the different tissues.