Figure 1.

Genetic crossing strategy. The starting PdL insertion on the X chromosome PdL(X)A was mobilized using the Δ2-3 transposase source to generate approximately 10,000 new PdL insertions on the second and third chromosomes. Chromosomes potentially bearing new PdL insertions are indicated by asterisks and were recovered in males that also contained an rtTA transactivator construct. The males were allowed to age in the presence of DOX in staggered cohorts of approximately 1,200 each and were individually mated to balancer virgins. Stable PdL insertion lines were recovered for the longest-lived (approximately 1.4% of the males in each cohort). A total of 110 lines were identified using rtTA insertion rtTA(3)E2, and 34 lines with insertion rtTA(3)M1.