Effect of the Mbov_0496 mutation on gene expression of Mycoplasma bovis under normal and high potassium conditions

Cyclic di-AMP is an essential and ubiquitous second messenger that regulates bacterial potassium (K+) concentrations to maintain osmotic equilibrium. And its specific K+ regulation mechanism in Mycoplasma has rarely been investigated. We used the ruminant pathogen Mycoplasma bovis (M. bovis) to investigate this mechanism. We verified that MbovP496 is a c-di-AMP synthetase and its mutant T5.415 showed growth inhibition under high K+ condition. To deliver why the mutant strain T5.415 can regulate M. bovis growth, we held a RNA-seq analysis to reveal that the differentially expressed genes between WT and T5.415 under normal condition and high K+ condition. The K+ transport pathways and metabolism related pathways were enriched. In conclusion, we found that the mutation of c-di-AMP synthetase, MbovP496 can broadly influence not only the metal ions transport pathway, but also has an effect on metabolism pathways,which could significantly contribute to understanding the regulation of growth by c-di-AMP synthetase in mycoplasmas. Overall design: RNA-seq profiling of wild-type Mycoplasma bovis and the MbovP496 mutant T5.415 under normal PPLO culture conditions and PPLO medium supplemented with 50 mM K+