Open AccessON THE EXISTENCE OF A G o ‐PHASE IN THE CELL CYCLE
Author(s) -
Burns F. J.,
Tannock I. F.
Publication year - 1970
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/j.1365-2184.1970.tb00340.x
Subject(s) - mitosis , constant (computer programming) , labelling , phase (matter) , population , cell division , chemistry , biology , cell , microbiology and biotechnology , biochemistry , demography , organic chemistry , sociology , computer science , programming language
The model is based on the assumption that the cell cycle contains a G o ‐phase which cells leave randomly with a constant probability per unit time, γ. After leaving the G o ‐phase, the cells enter the C‐phase which ends with cell division. The C‐phase and its constituent phases, the‘true’G 1 ‐phase, the S‐phase, the G 2 ‐phase and mitosis are assumed to have constant durations of T , T 1 T s , T 2 and T m , respectively. For renewal tissue it is assumed that the probability per unit time of being lost from the population is a constant for all cells irrespective of their position in the cycle. The labelled mitosis curve and labelling index for continuous labelling are derived in terms of γ, T , and T s . The model generates labelled mitosis curves which damp quickly and reach a constant value of twice the initial labelling index, if the mean duration of the G o ‐phase is sufficiently long. It is shown that the predicted labelled mitosis and continuous labelling curves agree reasonably well with the experimental curves for the hamster cheek pouch if T has a value of about 60 hr. Data are presented for the rat dorsal epidermis which support the assumption that there is a constant probability per unit time of a cell being released from the G o ‐phase.