Gene conversion using Abd-BFab7-2.tHa.prom-scs as a donor template, which results in the endogenous Fab-7 sequences being replaced with those in Abd-BFab7-2.tHa.prom-scs (producing a chromosome with the Fab-72 deletion with scsprom inserted upstream of it, with the scsprom fragment oriented such that the BamHI end is next to the Fab-72 deletion endpoint).
Segments A3 to A6 are transformed into a mixture of A2-A3 identity in homozygous males. Heterozygous flies are wild type.