April 1993; first author's address updated April 1994, last change May 1994 Los Alamos Unclassified Report 92-2942 (also known as YALEU/DCS/RR/922; submitted for publication), entitled Model for cooperative control of positional information in Drosophila by bicoid and maternal hunchback by John Reinitz (Yale, Medical Informatics [1]), Eric Mjolsness (Yale, Computer Science), and David H. Sharp (Los Alamos, Theoretical Division) [1] Current address: Brookdale Center for Molecular Biology, Mount Sinai Medical School, NYC, NY 10029 USA. Abstract: The blastoderm of the fruit fly Drosophila melanogaster is unusually well suited for analysis of fundamental questions in animal development. One such question is how genes specify the positional information which determines the developmental pathways (fate) of cells at appropriate spatial locations. In this paper we propose a dynamical model of gene regulation which explicitly describes how positional information is used in the blastoderm. The model is applied to analyze important experimental 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 hunchback genes. There are two files, Positional_Info.ps.Z and Positional_Info.ps The files are identical, except that the one with .Z suffix was compressed using the Unix compress utility. You must use the binary mode of FTP to transfer the first file with the .Z suffix. These files were generated from TeX and contain included postscript figures. They are as portable for printing as I can make them, but I can only print them on what is available to me. The file prints correctly under Unix on a SparcPrinter or Personal Laserwriter. If you get this file and can't print it, please get in touch with me at the address below. On Unix, print the file like this: zcat Positional_Info.ps.Z | lpr or lpr Positional_Info.ps Note that on a System V flavored unix, you may need "lp" instead of "lpr". Any questions, comments, etc. to reinitz@kruppel.molbio.mssm.edu 212-241-1952