Limits...
Are Myxobacteria intelligent?

Kaiser D - Front Microbiol (2013)

Bottom Line: Both swarming-growth and starvation-induced fruiting body development depend upon the specificity and effectiveness of signals passed between cells.After separating, both cells move on to make similar, transient connections with other cells.Eventually, the signal spreads across a prescribed population of communicating cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, Stanford University School of Medicine Stanford, CA, USA.

ABSTRACT
"Intelligence" is understood in different ways. Because humans are proud of their ability to speak, intelligence often includes the ability to communicate with others, to plan for the future, and to solve frequently encountered problems. Myxobacteria are among the most socially adept and ubiquitous of bacteria that live in the soil. To survive in nature, Myxobacteria communicate with their peers, using signals that elicit specific responses. Both swarming-growth and starvation-induced fruiting body development depend upon the specificity and effectiveness of signals passed between cells. Dynamic swarms spread outward, forming regular multi-cellular and multi-layered structures as they spread. Several different extra-cellular signals have been identified for fruiting body development and one is hypothesized for swarm development. Some extra-cellular signals are small, diffusible molecules. Others are protein molecules. The swarm signal appears to consist of structurally complex, protein to protein, contact junctions between pairs of side by side aligned cells. Each junction persists for less than a minute before disconnecting. After separating, both cells move on to make similar, transient connections with other cells. Eventually, the signal spreads across a prescribed population of communicating cells.

No MeSH data available.


Swarm of wild type M. xanthus on a CTT agar plate. The photo was taken after 7 days of incubation at 20°C. The vertical red line at the bottom of the panel marks the 520 μm wide edge of the annulus. We observe annular cells to be growing exponentially at their maximum rate, as each cell continues to move. The swarm is a dynamic collection of interacting cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3824092&req=5

Figure 1: Swarm of wild type M. xanthus on a CTT agar plate. The photo was taken after 7 days of incubation at 20°C. The vertical red line at the bottom of the panel marks the 520 μm wide edge of the annulus. We observe annular cells to be growing exponentially at their maximum rate, as each cell continues to move. The swarm is a dynamic collection of interacting cells.

Mentions: Myxobacteria are facultative multicellular organisms, a quality particularly useful for the study of signaling between cells. Given a complete medium for liquid culture, these delta-proteobacteria (Goldman et al., 2006) grow as independent rod-shaped cells; growing cells are 5–7 μm in length and 0.5 μm in diameter. On a solid surface, these elongated cells move cooperatively in a multicellular swarm, while individual cells prefer to move in the direction of their long axis. Once they have grown to moderate cell densities, adjacent swarm cells tend to align with each other and to form rafts of moving cells (Kaiser and Warrick, 2011). Non-motile mutants form dense, sharp-edged, ordinary colonies whose cells are heaped on each other, lack organization (no rafts), and do not swarm. Moreover, non-motile mutants are unable to signal each other or to form organized fruiting body-like structures (Kroos et al., 1988). Thus, individual swarm cells seem to be recognizing and specifically interacting with each other in a swarm and as they proceed to develop fruiting bodies (Hagen et al., 1978; LaRossa et al., 1983). A swarm can spread at the same rate for more than 300 h (Kaiser and Warrick, 2011). The average speed of individual cells in a swarm can be measured accurately by the steady-state rate of swarm expansion. Figure 1 illustrates the perfect radial symmetry of an expanding swarm of Myxococcus xanthus.


Are Myxobacteria intelligent?

Kaiser D - Front Microbiol (2013)

Swarm of wild type M. xanthus on a CTT agar plate. The photo was taken after 7 days of incubation at 20°C. The vertical red line at the bottom of the panel marks the 520 μm wide edge of the annulus. We observe annular cells to be growing exponentially at their maximum rate, as each cell continues to move. The swarm is a dynamic collection of interacting cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3824092&req=5

Figure 1: Swarm of wild type M. xanthus on a CTT agar plate. The photo was taken after 7 days of incubation at 20°C. The vertical red line at the bottom of the panel marks the 520 μm wide edge of the annulus. We observe annular cells to be growing exponentially at their maximum rate, as each cell continues to move. The swarm is a dynamic collection of interacting cells.
Mentions: Myxobacteria are facultative multicellular organisms, a quality particularly useful for the study of signaling between cells. Given a complete medium for liquid culture, these delta-proteobacteria (Goldman et al., 2006) grow as independent rod-shaped cells; growing cells are 5–7 μm in length and 0.5 μm in diameter. On a solid surface, these elongated cells move cooperatively in a multicellular swarm, while individual cells prefer to move in the direction of their long axis. Once they have grown to moderate cell densities, adjacent swarm cells tend to align with each other and to form rafts of moving cells (Kaiser and Warrick, 2011). Non-motile mutants form dense, sharp-edged, ordinary colonies whose cells are heaped on each other, lack organization (no rafts), and do not swarm. Moreover, non-motile mutants are unable to signal each other or to form organized fruiting body-like structures (Kroos et al., 1988). Thus, individual swarm cells seem to be recognizing and specifically interacting with each other in a swarm and as they proceed to develop fruiting bodies (Hagen et al., 1978; LaRossa et al., 1983). A swarm can spread at the same rate for more than 300 h (Kaiser and Warrick, 2011). The average speed of individual cells in a swarm can be measured accurately by the steady-state rate of swarm expansion. Figure 1 illustrates the perfect radial symmetry of an expanding swarm of Myxococcus xanthus.

Bottom Line: Both swarming-growth and starvation-induced fruiting body development depend upon the specificity and effectiveness of signals passed between cells.After separating, both cells move on to make similar, transient connections with other cells.Eventually, the signal spreads across a prescribed population of communicating cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, Stanford University School of Medicine Stanford, CA, USA.

ABSTRACT
"Intelligence" is understood in different ways. Because humans are proud of their ability to speak, intelligence often includes the ability to communicate with others, to plan for the future, and to solve frequently encountered problems. Myxobacteria are among the most socially adept and ubiquitous of bacteria that live in the soil. To survive in nature, Myxobacteria communicate with their peers, using signals that elicit specific responses. Both swarming-growth and starvation-induced fruiting body development depend upon the specificity and effectiveness of signals passed between cells. Dynamic swarms spread outward, forming regular multi-cellular and multi-layered structures as they spread. Several different extra-cellular signals have been identified for fruiting body development and one is hypothesized for swarm development. Some extra-cellular signals are small, diffusible molecules. Others are protein molecules. The swarm signal appears to consist of structurally complex, protein to protein, contact junctions between pairs of side by side aligned cells. Each junction persists for less than a minute before disconnecting. After separating, both cells move on to make similar, transient connections with other cells. Eventually, the signal spreads across a prescribed population of communicating cells.

No MeSH data available.