Our lab studies the genomics of emergent behavior and the origins of multicellularity. We study the gram-negative delta-proteobacterium Myxococcus xanthus, a model organism for biofilms and biocomplexity. M. xanthus is exceptional in that it combines the genetic simplicity and experimental tractability of a prokaryote with the multicellular behavior characteristic of a eukaryote.
When starved, the cells of an M. xanthus biofilm coordinate their movement, creating visible dynamic patterns that culminate in the formation of multicellular structures called fruiting bodies. Each fruiting body contains approximately 1X105 cells, and the cells located within the center of each fruiting body differentiate into environmentally resistant spores. The transition to fruiting bodies with ordered structures and spatially and temporally coordinated cell differentiation takes as little as twelve hours and involves multiple stages.
An M. xanthus swarm is a distributed system; it is a collection of superposable automata whose distribution is transparent so that the system appears as one machine. Our goal is to understand how this self-organization is choreographed at the genomic level. We combine this analysis with data from expression profiling and comparative genomics to find genetic checkpoints, and to group genes into functional modules. Our immediate goal is to discover the genetic networks that coordinate the formation of fruiting bodies. From this, we hope to learn the basic rules of emergence. Articulating these rules will bring developmental biologists significantly closer to rationally modifying living structures at the genetic level.