UASt regulatory sequences drive expression of a signal peptide, the spGFP1-10 split-GFP protein fragment and Nrx-1 coding sequence starting from residue 107 (the Nrx-1 sequences target spGFP1-10 to the synaptic membrane). Designed for use in the 'GFP Reconstitution Across Synaptic Partners' (GRASP) technique (PMID:18255029).