UAS regulatory sequences drive expression of pros with mutations in the N7 motif that impair its liquid-liquid phase separation activity (amino acid replacements M828S, L838S, I846S, F861S and F868S). A protein domain known to drive liquid-liquid phase separation (the C-terminal intrinsically disordered region - amino acid residues 186-320 - of human HNRNPA1, see PMID:26406374), has been fused to the N-terminal end of the coding region. The coding sequence is also tagged with GFP.