Cell Cycle Synchronization of Gonyaulax polyedra by Filtration: Quantized Generation Times

Abstract

A size filtration method to synchronize cultures of the dinoflagellate Gonyaulax polyedra to the beginning of the G₁ phase has been developed. This technique selects newly born cells by two sequential filtrations, based on the fact that cell division is restricted to the beginning of the day, so that a decrease in cell volume occurs at this time. The fraction of synchronized cells immediately after the second filtration is about 90%; the procedures do not alter the free-running period or phase of glow rhythm, and the selected cells divide again in a few days. Applying this method, we have found that the generation times of this species in a light-dark cycle (LD 12:12) are indeed quantized to multiples of 24 hr, but are variable from generation to generation.

References

Barnett, A. (1969) Cell division: A second circadian clock system in Paramecium multimicronucleatum Science 164: 1417-1419.

Broda, H. , V.D. Gooch , W.R. Taylor , N. Aiuto , and J.W. Hastings (1986) Acquisition of circadian bioluminescence data in Gonyaulax and an effect of the measurement procedure on the period of the rhythm J. Biol. Rhythms 1: 251-263.

Bruce, V.G. (1970) Biological clock in Chlamydomonas reinhardii J. Protozool. 17: 328-333.

Edmunds, L.N., Jr. ( 1966) Studies on synchronously dividing cultures of Euglena gracilis Klebs (strain Z): III. Circadian components of cell division J. Cell Physiol. 67: 35-44.

Edmunds, L.N., Jr. ( 1974) In Mechanisms of Regulation of Plant Growth , R. L. Bieleski, A. R. Ferguson, and M. M. Cresswell, eds., pp. 287-297, Royal Society of New Zealand, Wellington, New Zealand.

Edmunds, L.N., Jr. , After, R.I. , Rosenthal, P.J. , Shen , W.-K. , and Woodward, J.R. (1979) Light effects in yeast: Persisting oscillations in cell division activity and amino acid transport in cultures of Saccaromyces cerevisiae entrained by light-dark cycles Photochem. Photobiol. 30: 595-601.

Guillard, R.R.L. , and J.H. Ryther (1962) Studies of marine plankton diatoms: I. Cyclotella nana Hustedt and Detonula confervacea Cleve. Canad J. Microbiol. 8: 229-239.

Hastings, J.W. (1960) Biochemical aspects of rhythms: Phase shifting by chemicals. Cold Spring Harbor Symp Quant. Biol. 25: 131-143.

Helmstetter, C.E. (1967) Rate of DNA synthesis during the division cycle of E. coli b/r J. Mol. Biol. 24: 417-427.

10.

Johnson, C.H. , and J.W. Hastings (1986) The elusive mechanism of the circadian clock Amer. Sci. 74: 29-36.

11.

Mcmurry, L. , and J.W. Hastings (1972) No desynchronization among four circadian rhythms in the unicellular alga, Gonyaulax polyedra Science 175: 1137-1139.

12.

Sweeney, B.M. , and J.W. Hastings (1958) Rhythmic cell division in populations of Gonyaulax polyedra J. Protozool. 5: 217-224.

13.

Taylor, W.R. , J.C. Dunlap , and J.W. Hastings (1982a) Inhibitors of the protein synthesis on 80S ribosomes phase shift the Gonyaulax clock J. Exp. Biol. 97: 121-136.

14.

Taylor, W.R. , S. Wilson , R. Presswood , and J.W. Hastings (1982b) Circadian rhythm data collection using the Apple II microcumpter J. Interdiscipl. Cycle Res. 13: 71-79.

15.

Volm, M. (1964) Die tagesperiodik der zellteilung von Paramecium bursaria Z. Vergl. Physiol. 48: 157-180.

16.

Vicker, M.G. , J. Becker , G. Gebauer , W. Schill , and L. Rensing (1988) Circadian rhythms of cell cycle processes in the marine dinoflagellate Gonyaulax polyedra Chronobiol. Int. 5: 5-17.

17.

Wille, J.J. , and C.F. Ehret (1968) Light synchronization of and endogenous circadian rhythm of cell division in Tetrahymena J. Protozool. 15: 785-788.