Development of a replicative plasmid for gene expression in Mycoplasma bovis

• A replicative plasmid system was developed for Mycoplasma bovis.
• The transformation conditions were optimized to improve transformation frequency.
• The plasmids served stably as extra-chromosomal elements during 30 passages.
• The heterologous protein β-galactosidase was expressed by this plasmid system.
• A FLAG tag-fused endogenous protein was expressed and detectable.

Mycoplasma bovis (M. bovis) is a pathogen related to a variety of disease syndromes that result in significant economic losses in the cattle industry. Here, a stable replicative plasmid system is developed for use in M. bovis, utilizing an origin of replication (oriC) region. Additionally, the heterologous protein β-galactosidase and a FLAG tag-fused endogenous protein were successfully expressed by this plasmid system. These findings provide evidence that this oriC-based vector is applicable for the study of M. bovis.