Abstract
In the last two decades, an increasing number of bacterial species have
been recognized that are able to generate a phenotypically diverse
population that shares an identical genotype. This ability is dependent
on a complex genetic regulatory network that includes cellular and
environmental signals, as well as stochastic elements. AmongBacilli , a broadly distributed family of Rap
(R esponse-regulator a spartyl p hosphate)
phosphatases is known to modulate the function of the main phenotypic
heterogeneity regulators by controlling their phosphorylation. Even
more, their related extracellular Phr (Ph osphataser egulator) peptides function as quorum sensing signals, creating
a cell-cell communication network that regulates the phenotypic
development of the entire population. In this review, we examine the
role that the Rap phosphatases and their Phr peptides play in the
regulation of B. subtilis phenotypic differentiation, and in
other members of the Bacillus genus. We also highlight the
contribution of these regulatory elements to the fitness of bacterial
cells and mobile genetic elements, e.g. prophages and conjugative
vectors.