A hallmark of living systems is their ability to generate complex spatial patterns at the molecular, cellular, and multicellular levels. Many such systems rely on coupled biochemical and genetic signaling mechanisms that can produce URLanization. Long-range order and patterning can also emerge, however, through purely mechanical interactions. Here, we study the starvation-induced aggregation of gliding Myxococcus xanthus bacteria and show that these cells phase separate by tuning their motility over time. By experimentally varying the density and speed of gliding cells, tracking individual cells in large populations, and comparing to simulations of a model of reversing Active Brownian Particles (ABPs), we show that cell aggregation can be understood with a single phase diagram in terms of  density and a dimensionless inverse rotational Peclet number that characterizes cell motility . We further track changes in motility of the wild-type during starvation and show that a reduction of the reversal frequencyand an increase in gliding speed change the rotational Peclet number to drive aggregation. Thus, M. xanthus evolved to take advantage of an active-matter phase transition that can be controlled through changes in motility at the individual cell levelwithout complex feedback and chemical communication between cells .
Combining high-resolution single cell tracking experiments with numerical simulations, we show that starvation-induced fruiting body (FB) formation in Myxococcus xanthus is a phase separation driven by cells that tune their motility over time. The phase separation can be understood in terms of cell density and a dimensionless Peclet number that captures cell motility through speed and reversal frequency. Our work suggests that M. xanthus take advantage of a self-driven non-equilibrium phase transition that can be controlled at the single cell level .
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A hallmark of living systems is their ability to generate complex spatial patterns at the molecular, cellular, and multicellular levels. Many such systems rely on coupled biochemical and genetic signaling mechanisms that can produce URLanization. Long-range order and patterning can also emerge, however, through purely mechanical interactions. Here, we study the
Combining high-resolution single cell tracking experiments with numerical simulations, we show that
R
aggregation of gliding Myxococcus xanthus bacteria and show that these cells phase separate by tuning
fruiting body (FB) formation in Myxococcus xanthus is a phase separation driven by cells that tune
R
By experimentally varying the density and speed of gliding cells, tracking individual cells in large populations, and comparing to simulations of a model of reversing Active Brownian Particles (ABPs), we show that cell aggregation
The phase separation
D
with a single phase diagram
A
cell
D
inverse rotational
R
characterizes cell motility . We further track changes in motility of the wild-type during starvation and show that a reduction of the reversal frequencyand an increase in gliding speed change the rotational Peclet number to drive aggregation. Thus,
captures cell motility through speed and reversal frequency. Our work suggests that
D
evolved to
R
an active-matter
a self-driven non-equilibrium
R
through changes in motility at the individual cell levelwithout complex feedback and chemical communication between cells
at the single cell level