Construct: A ribozyme directed against w is expressed under the control of a heat shock promoter.
Flies carrying two copies of LTSV\RBZhs.w in a wild-type background show no change in eye colour compared to wild-type.
The eye pigmentation of Df(1)w67c2 homozygotes carrying w+mW.hs is reduced if the flies are also carrying two copies of LTSV\RBZhs.w and are heat shocked for 1 hour at 37oC every 12 hours throughout development.