The stg FMW (first mitotic wave) cis-regulatory element, a 539bp sub-fragment of the stg VS (visual system) enhancer (a 4.8kb fragment located 52kb upstream of the stg promoter), is fused upstream of EGFP tagged with the Tag:PEST(mOdc) degradation sequence. The hth binding site in the stg FMW sequence has been mutated.