Insertion of a 9.2 kb roo-element at map position +4.9 relative to the transcription start site of w.
The wsp1 region has been cloned (Zachar and Bingham, 1982) and sequenced (O'Hare, Murphy, Levis and Rubin, 1984); it is located 1.0-1.9 kb upstream from the 5' end of the start of w+ transcription (Zachar and Bingham, 1982; O'Hare, Levis and Rubin, 1983). wsp1 shows sequence homology and behavior analogous to enhancer sequences (Davison, Chapman, Wedeen and Bingham, 1985). The lesions responsible for wsp1, wsp2 and wsp4 have been analyzed by sequencing cloned portions of these alleles; the breakpoints of wsp3 and wsp81d have also been established by molecular methods. wsp1 carries roo; the other alleles are molecular deletions. Sensitivity to the effect of su(wsp) on eye pigmentation is deleted by wsp81d but not by wsp3 (Davison, Chapman, Wedeen and Bingham, 1985). 8.7 kb insertion map site (kb): +4.92; Origin = insertion of wa copia; '-' values to left (telomere) end; '+' values to right (centromere) end. In spite of the variegated pattern of spots in the eye in this mutant, the transcript is like that of w+ in size, structure and amount (Levis et al., 1984; Pirrotta and Brockl, 1984).
Eye pigmentation of wsp1 animals is restored to almost wild type levels in east1 or easthop-7 homozygotes, or east1/easthop-7 transheterozygotes. wsp1 eye pigmentation is rescued to intermediate levels in east1 or easthop-7 heterozygotes.