Insertion lies within a 4kb region that represents a hot spot for P-element insertions and maps ~20kb upstream from the Class I cDNA which includes the spen ORF, and immediately upstream of (and slightly overlaps) the j1 cDNA that likely corresponds to the spen 5' UTR.
Insertion maps in the first exon or the first intron of the spen transcription unit.
Complements: kis07812.