BME Vegyészmérnöki és Biomérnöki Kar

Modeling the yeast cell cycle

Call identifier: OTKA-F
Project identifier: 34100
Project coordinator: Sveiczer Ákos
Coordinator department: Department of Applied Biotechnology and Food Science
Duration: January 1, 2001 – December 31, 2005
Total cost of the project: 2.316.000 Ft
Total cost of BME (project funding): 2.316.000 Ft (2.316.000 Ft)

Results

The aim of this five-year long scientific project was to investigate different aspects of the regulation of the fission yeast cell cycle. The applied methods were threefold, namely (i) analysis of microscopic films, (ii) mathematical modelling, and (iii) model fitting to experimental cell length data. (i) By studying cell diameter during whole cycles on time-lapse films, we have found that it is almost exclusively constant. However, in some individual wee1-6 mutant cells, the diameter significantly increased. We hypothesised that this phenomenon is probably connected to spontaneous diploidisation of these cells. (ii) We have developed a deterministic mathematical model of the fission yeast cell cycle, consisting of ordinary differential equations. It is able to describe endoreplication cycles of certain cell cycle mutants, mitotic catastrophe in others, as well as the phenotypes of cells overproducing either the cdc25 or the wee1 gene. A stochastic version of this model describes scattering in cell size and cycle time in a fission yeast population; this is based on differences in nuclear volume among the cells. (iii) We have also developed some statistically aided model selection criteria, which discriminates between exponential and (bi)linear growth patterns of individual cells.