After a 15 minute heat shock more than 70% embryos fail to hatch. More than 70% embryos exhibit preferential deletion of ftz-dependent bands of the ventral denticle belts. Co-expression of en::ftz^EFE.F175E.hs reduces the number of embryos with pattern defects.

Expression induced between 2.5 and 3 hours of development causes pattern deletions predominantly in the ftz-dependent parasegments. Less severe phenotype is fusion of pairs of denticle belts often at the edges and loss of naked cuticle anterior to the ftz-dependent bands, or partial loss of bands without loss of naked cuticle.