title: Temperature response of the cell cycle of Haplopappus gracilis in suspension culture and its significance to the G1 transition probability model.
abstract: The effects of temperature on the cell cycle of Haplopappus gracilis suspension cultures were analysed by the fraction of labelled mitoses method. Sphase in these cultures shows a different temperature optimum as compared to optima derived for G2 and mitosis. G1 phase has a much lower Q10 than the other cell cycle phases and shows no temperature optimum between 22 and 34° C. These results are discussed in relation to a transition probability model of the cell cycle proposed by Smith and Martin (Proc. Natl. Acad. Sci. USA 70, 1263-1267, 1973), in which each cell has a time independent probability of initiating the transition into another round of DNA replication and division. The implications of such a model for cell cycle analysis are discussed and a tentative model for a probabilistic transition trigger is advanced.
authors.affiliation: Genetics Department, Research School of Biological Sciences, The Australian National University, P.O. Box 475, 2601, Canberra, A.C.T., Australia.
authors.forename: A R
authors.initials: AR
authors.lastname: Gould