Transgene used to study the D. mauritiana mariner element. Consists of: P-element 5' end - a hybrid D. mauritiana mariner element - ry^+t7.2 marker - P-element 3' end. The hybrid mariner element sequence consists of the 5' end of the mariner element inserted in the M{}Dmau\w^pch allele (5' flanking sequence from the site of the insertion is also present) and the 3' end of the autonomous 'Mos1' mariner element, amplified from the Z8 D. simulans mosaic strain into which the D. mauritiana mariner element had been introduced genetically (3' flanking sequence from the site of the insertion is also present).