Genomic fragment that encompasses glo, mutated to carry a R52A amino acid substitution (mutates a residue important for binding of the UA-rich motif of the TCEIII stem loop of the nanos 3'UTR translational control element) and a W58A amino acid substitution (mutates a residue important for binding of the G-tract of the nanos 3'UTR translational control element). A EGFP tag has been inserted at the N-terminal end of the glo coding sequence.