The 0.8kb Fab-7 boundary element has been inserted between the two deletion break points in Abd-BFab8-305.
Almost all homozygous Abd-BFab8-305-Fab7 mutants (in a Abd-B05649 background) are wild type in appearance and are fertile. In rare cases flies patches of cells in A7 take on an A6 or A8 identity.
Abd-BFab8-305-Fab7, Abd-B05649/Df(3R)R59 mutants display two distinct phenotypes; in some flies the A7 segments take on features characteristic of the A6 segment (a wider sternite with bristles oriented towards the lateral side) and in others they take on features normally seen in A8 (absence of trichomes). The phenotype appears identical regardless of the orientation of the insertion.