Abstract:[Objective] The membrane proteins of Myxococcus xanthus, a model organism for studying prokaryotic development, remain an under-explored territory. [Methods] Putative outer membrane protein (OMP)-encoding ORFs were selected from Myxococcus xanthus genome using six computational algorithms. With lacZ as a reporter, we monitored the expression profiles of these genes during vegetative growth and development. [Results] Eleven putative OMPs have been identified based on bioinformatic analysis. Increased expression during development was found in two genes, MXAN3106 and MXAN3883, which were predicted to encode protein transporters of the secretin family and the fimbrial usher protein (FUP) family, respectively. The remaining nine genes that code for TonB-dependent receptors or efflux proteins exhibited a decreased expression or remained at a very low expression level after initiation of development. [Conclusion] Our data suggest that for M. xanthus, switching from growth to development is associated with a dramatic change in the expression pattern of membrane proteins.