MODEL FOR COOPERATIVE CONTROL OF POSITIONAL INFORMATION IN DROSOPHILABY BICOID AND MATERNAL HUNCHBACK

The blastoderm of the fruit fly Drosophila melanogaster is unusually w ell suited for analysis of fundamental questions in animal development . One such question is how genes specify the positional information wh ich determines the developmental pathways (fate) of cells at appropria te spatial locations. In this paper we propose a dynamical model of ge ne regulation which explicitly describes how positional information is used in the blastoderm. The model is applied to analyze important exp erimental findings on the dependence of cell fate on the concentration of the Bicoid morphogen. The model shows that positional information in the presumptive middle body is cooperatively determined by maternal products of the bicoid and hunchbach genes. (C) 1995 Wiley-Liss, Inc.