Mycoplasma ovipneumoniae is considered as an important pathogen of small ruminants, but its antigenic proteins are not well known so far. In this study, we cloned the EF-Tu gene of M. ovipneumoniae and analyzed the molecular features of the gene and its coding protein for the first time. The gene was then expressed in E.coli and the antigenicity of the coding protein was evaluated as well. The EF-Tu gene of M. ovipneumoniae is 1209 bp in length, encodes 402 amino acids, and shares the highest DNA sequence identity of 87.5% and deduced amino acid sequence identity of 97.8% with those of M. hyopneumoniae, respectively. The recombinant EF-Tu protein can react with the polyclonal antiserum of M. ovipneumoniae and can induce humoral immune responses in mice, which indicated that the EF-Tu may be used as a candidate protein in developing the technologies to control the disease.

Key words: Antigenicity, EF-Tu, Mycoplasma ovipneumoniae