The P{EP}CG2003EP3204 insertion maps within both CG2003 and heph (overlapping genes on opposite strands).
Expression of hephEP3204 under the control of Scer\GAL4nos.UTR.T:Hsim\VP16 (the animals are initially raised at 18oC and are then shifted to 29oC after 7 days) results in a complete loss of early germ cells (stem cells, gonialblasts and spermatogonia) in the testis. This defect is seen in at least 50% of testes examined.