Sequence encoding a Disc\RFPDsRed(T1).3xP3.cHa marker flanked by termini from the Tni\piggyBac transposable element has been inserted into Agps, downstream of the Agps start codon in the first exon. The marker is oriented in the opposite orientation to the direction of Agps transcription. The mutation results in a frameshift and a premature stop codon.