Drops of dense suspension of the F strain selleckchem were planted as smears of increasing diameter. As shown in Figure 7c, up to a critical diameter, roughly corresponding to the outer diameter of the interstitial circle of a normal F colony, the cells could still coordinate their
actions towards a full-fledged colony, albeit not with a full success. If compared with the standard F pattern, the central navel always occupied the whole area of planting, leaving to the interstitial ring only the space remaining to the critical diameter. Should the diameter of planting reach (or exceed) this critical diameter, no room was left for the interstitial circle, and the body turned into a macula, as predicted by our formal model. Figure 7 Simulation of inoculum geometry effects. a. Encounters of rimmed colonies. Profiles of mature colonies (including quorum levels) in the first find more generation after growth cessation. Inoculum position indicated by black dots. Colonies sharing the same substrate are smaller and reach maturity sooner than singletons, and develop a common rim if planted sufficiently close together. b. Effects of inoculum size in buy VX-680 simulated plantings by dropping. Top – number of generations required to reach final colony size, bottom – diameter of distinct
colony parts depending on initial inoculum size. Note that the simulation marked by the arrow resulted only in an imperfect, shallow rim, and simulations with larger inocula yielded maculae without a distinctive rim. Simulation
parameters were as for colony 1 in Figure 6b, c. c. Experimentally observed dependence of colony proportions (at day 7) on area of Dichloromethane dehalogenase planting. Increasing the planting area leads to the expansion of the red center at the expense of the interstitial circle. Above 10 mm of planting diameter (i.e. standard diameter of the circle; dashed line), the circle disappears totally, and the resulting body grows towards a macula. Discussion Highly structured bacterial bodies (mats, plaques, stromatolites, colonies, etc., containing astronomical amounts of cells belonging to hundreds of species) apparently represent the “”default”" way of living of most bacteria [25–34]. How do such bodies come into existence? Are they ad hoc contraptions, molded solely, or predominantly, by the external environment? A result from an ecological succession, a game played by well-trained players? Or, finally, may an analogy of ontogeny be assumed [23], similar to ontogeny in, e.g. mycobacteria, streptomycetes, slime molds, yeasts, or even plants or animals? Our experiments with a single clone or a pair of clones, each giving well-developed colonies with finite growth, may provide initial insight into the processes of bacterial body formation. Apparently, there exists an elaborated network of communicative signals mutually affecting bacterial bodies, so the first hypothesis can be safely dismissed.