Data for: Extensive cellular multi-tasking within Bacillus subtilis biofilms

Bacillus subtilis is a soil-dwelling bacterium that can form biofilms, or
communities of cells surrounded by a self-produced extracellular matrix.
In biofilms, genetically identical cells often exhibit heterogeneous
transcriptional phenotypes, so that subpopulations of cells carry out
essential yet costly cellular processes that allow the entire population
to thrive. Surprisingly, the extent of phenotypic heterogeneity and the
relationships between subpopulations of cells within biofilms of even in
well-studied bacterial systems like B. subtilis remains largely unknown.
To determine relationships between these subpopulations of cells,
we created 182 strains containing pairwise combinations of fluorescent
transcriptional reporters for the expression state of 14 different genes
associated with potential cellular subpopulations. We determined the
spatial organization of the expression of these genes within biofilms
using confocal microscopy, which revealed that many reporters localized to
distinct areas of the biofilm, some of which were co-localized. We used
flow cytometry to quantify reporter coexpression, which revealed that many
cells “multi-task,” simultaneously expressing two reporters. These data
indicate that prior models describing B. subtilis cells as differentiating
into specific cell types, each with a specific task or function, were
oversimplified. Only a few subpopulations of cells, including surfactin
and plipastatin producers, as well as sporulating and competent cells,
appear to have distinct roles based on the set of genes examined here.
These data will provide us with a framework with which to further study
and make predictions about the roles of diverse cell phenotypes in B.
subtilis biofilms.