Mutation of the core of the N motif to Ala residues (NEANERL to NEAAAAL).
Expression of m4N1.Scer\UAS.T:Zzzz\FLAG under the control of Scer\GAL4sca-537.4 results in the production of extra bristles (average 10.5 extra bristles per fly, total of 26 bristle positions on the notum and head assayed).