A Push-Pull Model for Nematode Sperm Amoeboid Motility

A Push-Pull Model for Nematode Sperm Amoeboid Motility 

Bottino et al. (2002) generated a physical model of nematode sperm motility based on these concepts and experimentally determined properties of the system. By simulating the addition of new MSP filaments at the leading edge of the cell coupled to MSP filament depolymerization near 

The principles of the push-pull model probably apply generally to amoeboid cell motility. Indeed, a consensus is developing that in both sperm and actin-based crawling cells the force for protrusion is derived from localized cytoskeletal assembly (reviewed by Pollard and Borisy, 2003). However, as applied to nematode sperm locomotion, the model envisions that lamellipod extension and cell body retraction are linked reciprocally to the polymerization state of the cytoskeleton. The lack of structural polarity of MSP filaments, the precise localization of cytoskeletal polymerization and depolymerization at opposite ends of the fiber complexes, and insights gained from reconstitution of cytoskeletal dynamics and motility in vitro and in vivo all support the conclusion that nematode sperm move without using motor proteins and that, instead, they rely on 

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