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 2986-2991 (FTLKDH, within the third 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.