One-dimensional spatial patterning along mitotic chromosomes: A mechanical basis for macroscopic morphogenesis

Significance Spatial patterns are a prominent and interesting feature of both biological and physical systems. We have discovered that mammalian mitotic chromosomes, which comprise two closely associated sister chromatids, exhibit two interesting spatial patterns. In one pattern, the structural axis of each chromatid acquires sequential partial helices of alternating handedness. In the other, an array of evenly spaced bridges links these two axes. Development of any spatial pattern requires communication within the system. We present a constellation of observations suggesting that these patterns are related and are promoted by a mechanical mechanism in which the communication required for development of patterns arises from redistribution of mechanical stress. Models involving bonded chromatin/axis bilayers and Kirchhoff–Love theory for elastic rods are discussed.