Boundary-driven scaling of Turing patterns and bacterial chromosomes*

The interplay between the internal architecture of a cell and its confining boundary is of fundamental importance for development and survival. We study the principles of such interplay by developing new nanofabrication and microfluidic tools to precisely manipulate bacterial cell shape and size, which we then combine with genetics, microscopy, and computational tools to quantitatively dissect organizational patterns of proteins and chromosomes. Two intriguing scaling phenomena have emerged in our experiments. First, Min protein oscillations, a division regulator, adapt the length scale of their dynamic gradients to cell length, a property unexpected from their Turing mechanism that historically were expected to have a fixed wavelength. Second, chromosome size scales with cell size nonlinearly, a property that has not been described theoretically. We will propose the underlying principles that drive these phenomena and also invoke discussions on the general advantage of organizational mechanisms in cells that exploit boundary effect.