The loxP cassette present in Su(H)gwt.w+ has been excised. The gene encodes the wild-type Su(H) coding region. Part of the first intron is duplicated compared to wild type, to avoid possible splicing defects due to the presence of the residual attR site. A single loxP site is also present in the 3'UTR.
Su(H)gwt flies are indistinguishable from wild-type.