| dc.description.abstract | Many bacteria survive harsh environments and facilitate their dispersion by developing vegetative cells into dormant spores. Gram-positive bacteria, such as Bacillus subtilis, have been used as model organisms for bacterial sporulation. In these bacteria, vegetative cells initiate sporulation by DNA replication followed by asymmetric cell division, after which the smaller daughter cells mature into spores. Some Gram-negative bacteria, such as Myxococcus xanthus, can also form spores. In contrast to Gram-positive bacteria, DNA replication, but not cell division, is required for M. xanthus sporulation. Instead, the entire rod-shaped vegetative cells directly transform into spherical spores. I hypothesize that the sporulation of Gram-positive and negative bacteria has evolved from a common mechanism that involves cell division. Amidases are the cell wall hydrolases which could potentially participate both the separation of daughter cells during division and the rod-to-sphere transition during sporulation. To search for this missing link between sporulation and division in M. xanthus, I systematically knocked out all the amidases in M. xanthus and identified one dual-functional amidase, DfaA, essential for both division and sporulation. I propose to investigate the spatial and temporal regulation of DfaA and elucidate the hidden connection between cell division and sporulation in Gram-negative bacteria. | |
