Flagellar elongation and shortening in Chlamydomonas. III. structures attached to the tips of flagellar microtubules and their relationship to the directionality of flagellar microtubule assembly.
Open Access
- 1 September 1977
- journal article
- research article
- Published by Rockefeller University Press in The Journal of cell biology
- Vol. 74 (3), 747-759
- https://doi.org/10.1083/jcb.74.3.747
Abstract
Two structures on the distal ends of Chlamydomonas flagellar microtubules are described. One of these, the central microbutule cap, attaches the distal ends of the central pair microtubules to the tip of the flagellar membrane. In addition, filaments, called distal filaments, are observed attached to the ends of the A-tubules of the outer doublet microtubules. Inasmuch as earlier studies suggested that flagellar elongation in vivo occurs principally by the distal addition of sublnits and because it has been shown that brain tubulin assembles in vitro primarily onto the distal ends of both central and outer doublet microtubules, the presence of the cap and distal filaments was quantitated during flagellar resorption and elongation. The results showed that the cap remains attached to the central microtubules throughout flagellar resorption and elongation. The cap was also found to block the in vitro assembly of neurotubules onto the distal ends of the central microtubules. Conversely, the distal filaments apparently do not block the assembly of neurotubules onto the ends of the outer doublets. During flagellar elongation, the distal ends of the outer doublets are often found to form sheets of protofilaments similar to those observed on the elongating ends of neurotubules being assembled in vitro. These results suggest that the outer doublet microtubules elongate by the distal addition of subunits, whereas the two central microtubules assemble by the addition of subunits to the proximal ends.This publication has 24 references indexed in Scilit:
- Splayed Tetrahymena cilia. A system for analyzing sliding and axonemal spoke arrangements.The Journal of cell biology, 1976
- Electron-microscopic study of the spindle and chromosome movement in the yeast Saccharomyces CerevisiaeJournal of Cell Science, 1976
- Microtubule-associated proteins and the stimulation of tubulin assembly in vitroBiochemistry, 1976
- Ultrastructure of mitosis in the cowpea rust fungus Uromyces phaseoli var. Vignae.The Journal of cell biology, 1976
- Mitosis in FungiInternational Review of Cytology, 1976
- Directionality of Brain Microtubule Assembly In VitroProceedings of the National Academy of Sciences, 1974
- Comparative isolation of cilia and flagella from the lamellibranch mollusc, Aequipecten IrradiansJournal of Cell Science, 1973
- Further observations on the ultrastructure of cilia from Tetrahymen a pyriformisExperimental Cell Research, 1972
- THE STRUCTURE AND FORMATION OF CILIA AND FILAMENTS IN RUMEN PROTOZOAThe Journal of cell biology, 1964
- NUTRITIONAL STUDIES WITH CHLAMYDOMONAS REINHARDIAnnals of the New York Academy of Sciences, 1953