Isolation, sequence analysis and expression profile of a novel swine gene differentially expressed in the Longissimus dorsi muscle tissues from LandracexLarge white cross-combination.

The mRNA differential display technique was performed to investigate the differences in gene expression in the Longissimus dorsi muscle tissues from LandracexLarge White cross-combination. One novel gene that was differentially expressed was identified using semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and its complete cDNA sequence was obtained using the rapid amplification of cDNA ends (RACE) method. The nucleotide sequence of the gene is not homologous to any of the known porcine genes. The sequence prediction analysis revealed that the open reading frame of this gene encodes a protein of 260 amino acids that contains the putative conserved domain of the carbonic anhydrase, and this protein has high homology with the carbonic anhydrase III (CA-III) of four species mouse (91%), horse (91%), rat (89%) and human (86%)-so that it can be defined as swine carbonic anhydrase III. The phylogenetic tree analysis revealed that the swine CA-III has a closer genetic relationship with the horse CA-III than with those of mouse, rat and human. The tissue expression analysis indicated that the swine CA-III gene is generally expressed in most tissues. Our experiment is the first to establish the primary foundation for further research on the swine CA-III gene.