ON MODELING OF GENE EXPRESSION PATTERNS IN THE DROSOPHILA EMBRYO BY THE GENE CIRCUIT METHOD

We review some recent results of modeling the pattern formation by segmentation genes during the early development of the Drosophila embryo. The study of gene expression patterns is based on the “gene circuit” method consisting of four steps: obtaining gene expression experimental data, formulating a model, fitting the model to the data, and inferring new biology from the analysis of results. The biological data has the form of processed images of immunostained embryos and is adopted in the form of concentration curves for proteins coded by various segmentation genes averaged over many embryos. The model is formulated as deterministic reaction-diffusion equations with protein concentrations in many cell nuclei as state variables. The values of parameters in the model are calculated by fitting the solution of model equations to the experimental concentration curves. We also describe how the gene circuit approach allows one to elucidate a role in the pattern formation played by nuclear cleavages in the developing embryo.