UASp regulatory sequences drive expression of the Rho1 coding sequence (amplified from the LD03419 cDNA clone), mutated to carry a G14V amino acid substitution (this results in a constitutively active protein). The coding sequence is tagged with mClover2. Sequence consisting of the nanos translational control element (TCE) and the pgc 3'UTR are present downstream of the coding sequence; this targets expression of the protein to the primordial germ cells.