Rotation and twist of the central-pair microtubules in the cilia of Paramecium.

摘要: The orientation and configuration of the central-pair microtubules in cilia were studied by serial thin-section analysis "instantaneously fixed" paramecia. Cilia frozen various positions metachronal waves such a fixation. spatial sequence these across wave represents temporal during active beat cycle cilium. Systematic shifts indicate that central pair rotates 360 degrees counterclockwise (viewed from outside) with each ciliary (C. K. Omoto, 1979, Thesis, University Wisconsin, Madison; C. Omoto Kung, Nature [Lond.] 279:532-534). This is true even for paramecia different directions effective stroke as forward- or backward-swimming cells. systematic cannot be seen Ni++-paralyzed cells sluggish mutants which do not have waves. Both thick-section high-voltage electron microscopy show whenever twist seen, it always left-handed. consistent hypothesis continuously rotation originating at base That most likely respect to peripheral tubules well cell surface discussed. These results are incorporated into model complex component regulation mechanism needed three-dimensional movement.