The endogenous 4.5kb Dscam1 promoter region regulates expression of a full-length Dscam1 cDNA, which is tagged at the C-terminal end with GFP. The Dscam1 sequences contain the alternative exons 4.3, 6.36, 9.25 and 17.2. Exon 19 is absent and exon 23 is present.