GENETIC-DETERMINANTS OF SENSE ORGAN IDENTITY IN DROSOPHILA - REGULATORY INTERACTIONS BETWEEN CUT AND POXN

Two genes involved in defining the type of sense organ have been ident ified in Drosophila. The gene cut differentiates the external sense or gans (where it is expressed) from the chordotonal organs (where it is not); among the external sense organs poxn differentiates the poly-inn ervated organs (where it is expressed) from the mono-innervated organs (where it is not), Here we show that the expression of poxn in normal embryos does not depend on cut, and that poxn is capable of inducing the expression of cut. We have identified a small domain of the very l arge cut regulatory region as a likely target for activation by poxn.