Cell lineage of homeotic mutants of Drosophila

Abstract The homeotic genes specify the development of specific groups of precursor cells. They establish the correct state of determination of the different primordia. Cell lineage analysis has been particularly useful in studying the mode of action of homeotic genes. The main findings are: (i) most, perhaps all, the homeotic genes are required by every cell of the corresponding primordium (that is, they are cell autonomous); (ii) they act on anatomical units defined by compartment boundaries and including one or more compartments, (iii) most, but not all, homeotic genes are required until the end of the larval period; (iv) the homeotic genes act in combination so that the appropriate development of a given primordium may be established by the contribution of several homeotic genes.