A sequence cassette encoding 1. an FRT cassette containing the Tag:V5 tag followed by a stop codon, 2. a Tag:FLAG tag followed by a stop codon and 3. a loxP cassette containing a Disc\RFPmCh.3xP3.cUa marker, has been inserted into the endogenous Fili locus at the C-terminal end of the coding sequence. This results in a conditionally-tagged protein; in the absence of FLP recombinase the expressed protein is tagged with Tag:V5. If the FRT cassette is excised, the expressed protein is instead tagged with Tag:FLAG.