Homeogene expression patterns and chromosomal imprinting

In both mouse and Drosophila, Antennapedia-like homeobox-containing genes (homeogenes) display a strict correspondence between the order of genes (3' to 5') along the chromosome and the order of their expression domains (anterior to posterior) in the developing embryo. We show here how this, and other points of similarity, may indicate that both species use a common mechanism of chromosomal imprinting in order to retain cellular memory of homeogene expression patterns throughout embryonic development.