Fitting a model to the growth of yeast colonies.

When yeast cells reproduce, scars are left on the parent cell where the offspring has budded. Using a branching process model, it is possible to obtain the expectations of numbers of cells with 0, 1, 2, ... offspring. In this paper, theoretical results are tested against empirical data for three types of yeast cells. We examine the hypothesis that birth and death rates of cells with no previus offspring may differ from those of cells with one or more offspring. It is suggested that the oscillatory empricial results for the proportions of cells with 0, 1, 2, 3 and 4 offspring may be due to different mean budding times for these cells.