Wenren, LarissaSullivan, N. L.Cardarelli, L.Septer, Alecia NoelleGibbs, Karine2013-11-132013Wenren, Larissa M., Nora L. Sullivan, Lia Cardarelli, Alecia N. Septer, and Karine A. Gibbs. 2013. Two independent pathways for self-recognition in proteus mirabilis are linked by type VI-dependent export. mBio 4(4): e00374-13.2150-7511http://nrs.harvard.edu/urn-3:HUL.InstRepos:11315443Swarming colonies of the bacterium Proteus mirabilis are capable of self-recognition and territorial behavior. Swarms of independent P. mirabilis isolates can recognize each other as foreign and establish a visible boundary where they meet; in contrast, genetically identical swarms merge. The ids genes, which encode self-identity proteins, are necessary but not sufficient for this territorial behavior. Here we have identified two new gene clusters: one (idr) encodes rhs-related products, and another (tss) encodes a putative type VI secretion (T6S) apparatus. The Ids and Idr proteins function independently of each other in extracellular transport and in territorial behaviors; however, these self-recognition systems are linked via this type VI secretion system. The T6S system is required for export of select Ids and Idr proteins. Our results provide a mechanistic and physiological basis for the fundamental behaviors of self-recognition and territoriality in a bacterial model system.en-USsociomicrobiologytype VI secretionbacterial competitioncell-cell communicationself-recognitionJournal Article2013-08-06Larissa M. Wenren, Nora L. Sullivan, Lia Cardarelli, Alecia N. Septer, and Karine A. Gibbs2013-11-1310.1128/mBio.00374-13