The loxP cassette (containing a w+* marker) present in the progenitor allele has been excised.
wing margin bristle
Homozygous wgKO;NRT-wg.-loxP larvae grow faster and compete more effectively in co-culture with control animals than do homozygous wgKO;NRT-wg larvae.
The wing margin of homozygous wgKO;NRT-wg.-loxP flies occasionally shows loss of bristles.