Abstract
During mating of the alga Chlamydomonas, two biflagellate cells fuse to form a single quadriflagellate cell that contains two nuclei and a common cytoplasm. We have used this cell fusion during mating to transfer unassembled flagellar components from the cytoplasm of one Chlamydomonas cell into that of another in order to study in vivo the polarity of flagellar assembly. In the first series of experiments, sites of tubulin addition onto elongating flagellar axonemes were determined. Donor cells that had two full-length flagella and were expressing an epitope-tagged alpha-tubulin construct were mated (fused) with recipient cells that had two half-length flagella. Outgrowth of the shorter pair of flagella followed, using a common pool of precursors that now included epitope-tagged tubulin, resulting in quadriflagellates with four full-length flagella. Immunofluorescence and immunoelectron microscopy using an antiepitope antibody showed that both the outer doublet and central pair microtubules of the recipient cells' flagellar axonemes elongate solely by addition of new subunits at their distal ends. In a separate series of experiments, the polarity of assembly of a class of axonemal microtubule-associated structures, the radial spokes, was determined. Wild-type donor cells that had two full-length, motile flagella were mated with paralyzed recipient cells that had two full-length, radial spokeless flagella. Within 90 min after cell fusion, the previously paralyzed flagella became motile. Immunofluorescence microscopy using specific antiradial spoke protein antisera showed that radial spoke proteins appeared first at the tips of spokeless axonemes and gradually assembled toward the bases. Together, these results suggest that both tubulin and radial spoke proteins are transported to the tip of the flagellum before their assembly into flagellar structure.
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- Bloodgood R. A. Motility occurring in association with the surface of the Chlamydomonas flagellum. J Cell Biol. 1977 Dec;75(3):983–989. doi: 10.1083/jcb.75.3.983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Curry A. M., Williams B. D., Rosenbaum J. L. Sequence analysis reveals homology between two proteins of the flagellar radial spoke. Mol Cell Biol. 1992 Sep;12(9):3967–3977. doi: 10.1128/mcb.12.9.3967. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dentler W. L., Rosenbaum J. L. 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. J Cell Biol. 1977 Sep;74(3):747–759. doi: 10.1083/jcb.74.3.747. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dentler W. L. Structures linking the tips of ciliary and flagellar microtubules to the membrane. J Cell Sci. 1980 Apr;42:207–220. doi: 10.1242/jcs.42.1.207. [DOI] [PubMed] [Google Scholar]
- Diener D. R., Curry A. M., Johnson K. A., Williams B. D., Lefebvre P. A., Kindle K. L., Rosenbaum J. L. Rescue of a paralyzed-flagella mutant of Chlamydomonas by transformation. Proc Natl Acad Sci U S A. 1990 Aug;87(15):5739–5743. doi: 10.1073/pnas.87.15.5739. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dutcher S. K., Huang B., Luck D. J. Genetic dissection of the central pair microtubules of the flagella of Chlamydomonas reinhardtii. J Cell Biol. 1984 Jan;98(1):229–236. doi: 10.1083/jcb.98.1.229. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Field J., Nikawa J., Broek D., MacDonald B., Rodgers L., Wilson I. A., Lerner R. A., Wigler M. Purification of a RAS-responsive adenylyl cyclase complex from Saccharomyces cerevisiae by use of an epitope addition method. Mol Cell Biol. 1988 May;8(5):2159–2165. doi: 10.1128/mcb.8.5.2159. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Holmes J. A., Dutcher S. K. Cellular asymmetry in Chlamydomonas reinhardtii. J Cell Sci. 1989 Oct;94(Pt 2):273–285. doi: 10.1242/jcs.94.2.273. [DOI] [PubMed] [Google Scholar]
- Hopkins J. M. Subsidiary components of the flagella of Chlamydomonas reinhardii. J Cell Sci. 1970 Nov;7(3):823–839. doi: 10.1242/jcs.7.3.823. [DOI] [PubMed] [Google Scholar]
- Johnson K. A., Rosenbaum J. L. The basal bodies of Chlamydomonas reinhardtii do not contain immunologically detectable DNA. Cell. 1990 Aug 24;62(4):615–619. doi: 10.1016/0092-8674(90)90105-n. [DOI] [PubMed] [Google Scholar]
- Kindle K. L., Schnell R. A., Fernández E., Lefebvre P. A. Stable nuclear transformation of Chlamydomonas using the Chlamydomonas gene for nitrate reductase. J Cell Biol. 1989 Dec;109(6 Pt 1):2589–2601. doi: 10.1083/jcb.109.6.2589. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LEWIN R. A. Mutants of Chlamydomonas moewusii with impaired motility. J Gen Microbiol. 1954 Dec;11(3):358–363. doi: 10.1099/00221287-11-3-358. [DOI] [PubMed] [Google Scholar]
- Lefebvre P. A., Nordstrom S. A., Moulder J. E., Rosenbaum J. L. Flagellar elongation and shortening in Chlamydomonas. IV. Effects of flagellar detachment, regeneration, and resorption on the induction of flagellar protein synthesis. J Cell Biol. 1978 Jul;78(1):8–27. doi: 10.1083/jcb.78.1.8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Luck D., Piperno G., Ramanis Z., Huang B. Flagellar mutants of Chlamydomonas: studies of radial spoke-defective strains by dikaryon and revertant analysis. Proc Natl Acad Sci U S A. 1977 Aug;74(8):3456–3460. doi: 10.1073/pnas.74.8.3456. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mitchell D. R., Kang Y. Identification of oda6 as a Chlamydomonas dynein mutant by rescue with the wild-type gene. J Cell Biol. 1991 May;113(4):835–842. doi: 10.1083/jcb.113.4.835. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Piperno G., Huang B., Luck D. J. Two-dimensional analysis of flagellar proteins from wild-type and paralyzed mutants of Chlamydomonas reinhardtii. Proc Natl Acad Sci U S A. 1977 Apr;74(4):1600–1604. doi: 10.1073/pnas.74.4.1600. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Piperno G., Huang B., Ramanis Z., Luck D. J. Radial spokes of Chlamydomonas flagella: polypeptide composition and phosphorylation of stalk components. J Cell Biol. 1981 Jan;88(1):73–79. doi: 10.1083/jcb.88.1.73. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pringle J. R., Preston R. A., Adams A. E., Stearns T., Drubin D. G., Haarer B. K., Jones E. W. Fluorescence microscopy methods for yeast. Methods Cell Biol. 1989;31:357–435. doi: 10.1016/s0091-679x(08)61620-9. [DOI] [PubMed] [Google Scholar]
- RANDALL J., WARR J. R., HOPKINS J. M., MCVITTIE A. A SINGLE-GENE MUTATION OF CHLAMYDOMONAS REINHARDII AFFECTING MOTILITY: A GENETIC AND ELECTRON MICROSCOPE STUDY. Nature. 1964 Aug 29;203:912–914. doi: 10.1038/203912a0. [DOI] [PubMed] [Google Scholar]
- Rosenbaum J. L., Child F. M. Flagellar regeneration in protozoan flagellates. J Cell Biol. 1967 Jul;34(1):345–364. doi: 10.1083/jcb.34.1.345. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rosenbaum J. L., Moulder J. E., Ringo D. L. Flagellar elongation and shortening in Chlamydomonas. The use of cycloheximide and colchicine to study the synthesis and assembly of flagellar proteins. J Cell Biol. 1969 May;41(2):600–619. doi: 10.1083/jcb.41.2.600. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SAGER R., GRANICK S. Nutritional control of sexuality in Chlamydomonas reinhardi. J Gen Physiol. 1954 Jul 20;37(6):729–742. doi: 10.1085/jgp.37.6.729. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SAGER R., GRANICK S. Nutritional studies with Chlamydomonas reinhardi. Ann N Y Acad Sci. 1953 Oct 14;56(5):831–838. doi: 10.1111/j.1749-6632.1953.tb30261.x. [DOI] [PubMed] [Google Scholar]
- Schloss J. A., Silflow C. D., Rosenbaum J. L. mRNA abundance changes during flagellar regeneration in Chlamydomonas reinhardtii. Mol Cell Biol. 1984 Mar;4(3):424–434. doi: 10.1128/mcb.4.3.424. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Silflow C. D., Chisholm R. L., Conner T. W., Ranum L. P. The two alpha-tubulin genes of Chlamydomonas reinhardi code for slightly different proteins. Mol Cell Biol. 1985 Sep;5(9):2389–2398. doi: 10.1128/mcb.5.9.2389. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Warner F. D. New observations on flagellar fine structure. The relationship between matrix structure and the microtubule component of the axoneme. J Cell Biol. 1970 Oct;47(1):159–182. doi: 10.1083/jcb.47.1.159. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williams B. D., Mitchell D. R., Rosenbaum J. L. Molecular cloning and expression of flagellar radial spoke and dynein genes of Chlamydomonas. J Cell Biol. 1986 Jul;103(1):1–11. doi: 10.1083/jcb.103.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williams B. D., Velleca M. A., Curry A. M., Rosenbaum J. L. Molecular cloning and sequence analysis of the Chlamydomonas gene coding for radial spoke protein 3: flagellar mutation pf-14 is an ochre allele. J Cell Biol. 1989 Jul;109(1):235–245. doi: 10.1083/jcb.109.1.235. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Witman G. B., Carlson K., Rosenbaum J. L. Chlamydomonas flagella. II. The distribution of tubulins 1 and 2 in the outer doublet microtubules. J Cell Biol. 1972 Sep;54(3):540–555. doi: 10.1083/jcb.54.3.540. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Witman G. B., Plummer J., Sander G. Chlamydomonas flagellar mutants lacking radial spokes and central tubules. Structure, composition, and function of specific axonemal components. J Cell Biol. 1978 Mar;76(3):729–747. doi: 10.1083/jcb.76.3.729. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Witman G. B. The site of in vivo assembly of flagellar microtubules. Ann N Y Acad Sci. 1975 Jun 30;253:178–191. doi: 10.1111/j.1749-6632.1975.tb19199.x. [DOI] [PubMed] [Google Scholar]