Genomic sequence has been re-integrated into the attP site in TI{TI}stanΔ.attP, reconstituting a stan locus in which sequence encoding amino acids 2842-2847 (TNSNTL, within the first intracellular loop) has been replaced with SGGGGSGSSYSLESIGTSSGGGGS (this encodes an FRT site flanked by a linker on each side). In addition, the stan coding sequence is tagged with EGFP downstream of codon 355.