UAS regulatory sequences drive expression of N that is truncated at amino acid residue 2268. In addition, each of the three Tyr residues present in the truncated N intracellular domain sequence has been mutated to a non-phosphorylatable Phe residue (amino acid replacements Y1850F, Y1860F and Y2097F). The coding sequence is tagged at the C-terminal with 6xTag:MYC.