Mechanical behavior of primary cilia

摘要

We have developed a novel combined experimental/modeling approach to determine the mechanical propertiesof primary cilia. Specifically, we developed a large rotationformulation of cilia bending with fluid flow thataccounts for rotation at the base of the cilium, the initialshape of the cilium and fluid drag at high deflection angles.We also have obtained three dimensional configurations ofprimary cilia in their deformed configuration at 3Hzacquired with high-speed confocal microscopy. We founda wide variety of previously unreported bending shapesand behaviors. Cilia appear to deflect in smooth bendingshapes, rigid-body rotation, and in a hinged or kinked pattern.This suggests that both the axoneme and basal bodyanchorage are important to understanding deflection patterns.We also analyzed post-flow relaxation patterns.These results indicate that with removal of force, ciliaslowly return to their initial configuration. However, theyalso can return to a different configuration with “overcorrection”observed that suggests adaptation of mechanicalproperties. Results from our combined experimental andtheoretical approach suggest that the average flexuralrigidity of primary cilia might be higher than previouslyreported. In addition our findings indicate the mechanicsof primary cilia are potentially non-linear, richly varied,and mechanisms may exist to alter their mechanicalbehavior.