Partial duplication of the Dscam1 gene. The structure of the duplication is as follows; Dscam1 genomic sequences from the beginning of the transcription unit through to and including part of the intron following exon 2, cDNA sequences encoding Dscam1 exons 3-11 (which in this case encode the variable exons 4.3, 6.31 and 9.8), genomic Dscam1 sequences encoding exons 12-16, a single FRT site, a w[+] marker, genomic Dscam1 sequences including part of the intron following exon 2 through to exon 26 (the end of the transcription unit).