Negative stain EM shows actin filaments buckling at the contractomere to generate an actin ball. Negative-stain electron microscopy showing contractomere interacting with actin filaments (yellow arrows) via multiple electron densities (red arrows). Upper panel shows two rows of electron dense globular masses (red arrows) extending via linkers (blue arrows) from the contractomere to interact with actin filaments (yellow arrows). Lower panel is an enlarge image from Fig. 7 B showing interaction of actin filament (yellow arrows) with contractomere via multiple densities (red arrows) including a myosin-like coiled-coil linker extending from the membrane (blue arrows) and pear-shape myosin-like motor heads (red arrows). Scale bars are 100 nm.