Parameter estimation and determinability analysis applied to Drosophila gap gene circuits
1 CWI, Kruislaan 413, 1098 SJ Amsterdam, The Netherlands
2 Laboratory for Development & Evolution, University Museum of Zoology, Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
BMC Systems Biology 2008, 2:83 doi:10.1186/1752-0509-2-83Published: 25 September 2008
Mathematical modeling of real-life processes often requires the estimation of unknown parameters. Once the parameters are found by means of optimization, it is important to assess the quality of the parameter estimates, especially if parameter values are used to draw biological conclusions from the model.
In this paper we describe how the quality of parameter estimates can be analyzed. We apply our methodology to assess parameter determinability for gene circuit models of the gap gene network in early Drosophila embryos.
Our analysis shows that none of the parameters of the considered model can be determined individually with reasonable accuracy due to correlations between parameters. Therefore, the model cannot be used as a tool to infer quantitative regulatory weights. On the other hand, our results show that it is still possible to draw reliable qualitative conclusions on the regulatory topology of the gene network. Moreover, it improves previous analyses of the same model by allowing us to identify those interactions for which qualitative conclusions are reliable, and those for which they are ambiguous.