D. simulans sequence that is orthologous to a 390bp sub-fragment ('E6B') of the E6 enhancer from the cis-regulatory region of the 'shavenbaby' (svb) isoform of D. melanogaster ovo is fused upstream of lacZ. A mutated 32bp sequence from upstream of the E6B in D. sechellia is fused upstream of the D. simulans E6B sequence.