Sequence encoding the wild-type bicistronic wrm locus (encoding both wrm1 and wrm2 open reading frames) has been introduced into the attP site in TI{TI}wrm-ΔattP reconstituting a wild-type wrm locus. The wrm2 open reading frame is tagged at the C-terminal end with 'TwinStrep' (two copies of Tag:StrepII joined by a short linker). A loxP site and a Disc\RFPDsRed(T1).3xP3.cHa marker remains downstream of the inserted sequence.