Ubi-p63E promoter and 5'UTR sequences are fused upstream of a hybrid reporter composed of mCherry fused via a linker protein to EGFP. The codon usage of the EGFP coding sequence has been modified (by synonymous codon substitutions) so that 100% of the codons correspond to the most rarely used synonymous codon in the D. melanogaster genome. The codon usage of mCherry has not been altered (it is naturally enriched in codons corresponding to the most commonly used synonymous codon in the D. melanogaster genome).