Unravelling a diversity of cellular structures and aggregation dynamics during the early development of Myxococcus xanthus

Aggregation underlies collective dynamics of a diversity of organisms, enabling the formation of complex structures and emergent behaviours in interaction with the environment. Myxococcus xanthus, a social bacterium, is a valuable model for studying aggregation, particularly in the development and evolution of multicellularity. While the collective behaviour of M. xanthus has been largely studied under very crowded, ideal, conditions, there is a lack of understanding at not crowded or sparse conditions. In this work, we study the early stages of emergent collective behaviour of M. xanthus under nutrient-poor and low density conditions, uncovering the formation of diverse cellular structures with different shapes and sizes, ranging from individual cells to networks comprising thousands of cells. We study their motility patterns and their prevalence along development, and argue over their cross-scale role on the populations exploratory dynamics. This work contributes to understanding key, yet largely understudied, aspects in the early stages of multicellular development in myxobacteria, shedding light on the dynamics underlying aggregative processes in this and other taxa and study systems.