A 32kb genomic BAC fragment that encompasses brk. A multi-tag cassette composed of 3xTag:V5 and Tag:polyHis has been inserted at the C-terminal end of the brk coding sequence. An FRT cassette that encodes the mCherry coding sequence, tagged with Tag:CAAX(Unk) and followed by stop sequences, has been inserted in the brk 5'UTR. In the absence of FLP recombinase, the Tag:CAAX(Unk)-tagged mCherry sequence is expressed under the control of endogenous brk regulatory sequences, and the brk coding sequence is not expressed.