13XlexAop sequences are separated from two coding regions (themselves separated by a T2A peptide sequence) by an FRT cassette containing a stop signal. The first coding region, upstream of the T2A peptide is composed of the spGFP11 split fluorescent protein fragment fused to to a membrane targeting sequence (Tag:M(hCD4)) and a Tag:HA epitope (represented in FlyBase by the Avic\GFP^{spGFP11.13XLexAop2.FRT.Tag:M(hCD4),Tag:HA} allele). This protein is designed for use in a GRASP (GFP Reconstitution Across Synaptic Partners) assay, in which complementary split fluorescent protein fragments expressed on the extracellular membrane of different neurons can reconstitute a functional fluorescent protein at points of contact between the neurons. Downstream of the T2A peptide is a fusion protein composed of the 'D3' fragment of brp (amino acids 473-1226) fused to the mCherry fluorescent protein (this is represented in FlyBase by the Disc\RFP^{mCh.13XLexAop2.FRT.Tag:TS(brpS)} allele).