title: Parameter estimation and determinability analysis applied to Drosophila gap gene circuits.
abstract: BACKGROUND
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: CWI, Kruislaan 413, 1098 SJ Amsterdam, The Netherlands. M.Ashyraliyev@cwi.nl
authors.forename: Maksat
authors.initials: M
authors.lastname: Ashyraliyev
authors.forename: Johannes
authors.initials: J
authors.lastname: Jaeger
authors.forename: Joke G
authors.initials: JG
authors.lastname: Blom
mesh_terms: D000818:Animals; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D053263:Gene Regulatory Networks; D017344:Genes, Insect / Q000235:genetics*; D008957:Models, Genetic