title: The emergence of sarcomeric, graded-polarity and spindle-like patterns in bundles of short cytoskeletal polymers and two opposite molecular motors.
abstract: We use linear stability analysis and numerical solutions of partial differential equations to investigate pattern formation in the one-dimensional system of short dynamic polymers and one (plus-end directed) or two (one is plus-end, another minus-end directed) molecular motors. If polymer sliding and motor gliding rates are slow and/or the polymer turnover rate is fast, then the polymer-motor bundle has mixed polarity and homogeneous motor distribution. However, if motor gliding is fast, a sarcomeric pattern with periodic bands of alternating polymer polarity separated by motor aggregates evolves. On the other hand, if polymer sliding is fast, a graded-polarity bundle with motors at the center emerges. In the presence of the second, minus-end directed motor, the sarcomeric pattern is more ubiquitous, while the graded-polarity pattern is destabilized. However, if the minus-end motor is weaker than the plus-end directed one, and/or polymer nucleation is autocatalytic, and/or long polymers are present in the bundle, then a spindle-like architecture with a sorted-out polarity emerges with the plus-end motors at the center and minus-end motors at the edges. We discuss modeling implications for actin-myosin fibers and in vitro and meiotic spindles.
authors.affiliation: Department of Neurobiology, Physiology and Behavior, University of California, Davis, CA 95616, USA. ecraig@ucdavis.edu
authors.forename: E M
authors.initials: EM
authors.lastname: Craig
authors.forename: S
authors.initials: S
authors.lastname: Dey
authors.forename: A
authors.initials: A
authors.lastname: Mogilner
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D002465:Cell Movement; D016764:Cell Polarity; D003599:Cytoskeleton / Q000378:metabolism; D006801:Humans; D016547:Kinesins / Q000378:metabolism; D008540:Meiosis / Q000502:physiology; D008870:Microtubules / Q000378:metabolism; D056004:Molecular Dynamics Simulation; D009218:Myosins / Q000378:metabolism*; D011108:Polymers / Q000737:chemistry*; D012518:Sarcomeres / Q000502:physiology*; D008941:Spindle Apparatus / Q000502:physiology*
chemical_list: D000199:Actins; D011108:Polymers; D009218:Myosins; D016547:Kinesins