(A) The emergence of analogous nematic patterns at the colony edge. Two boxed areas are shown as examples on the right. The areas are chronologically aligned and show two types of topological defects characterized by two-dimensional nematic liquid crystals. (B) Time course images of the enlarged area indicated by a box on the colony edge. A key feature underlying the development of the unique cellular architecture is related to the cells adopting the two-dimensional, nematic liquid-crystal orientation (Doostmohammadi et al., 2018), in which cells are aligned tightly together to form the layered structure. Other bacteria, such as E. coli and B. subtilis, can produce nematic features, but only for short periods when the cells are allowed to grow two dimensionally (Dell’Arciprete et al., 2018; Yaman et al., 2019). In these species, collisions between the expanding layer of cells results in edge instability and buckling of the two-dimensional nematic order. Conversely, HS-3 filamentous cells have the remarkable ability to sustain an ordered structure.