Figure 2

Breeding strategy to generate double-transgenic hopper frogs. The F₂ hopper frogs were outcrossed with wild-type animals and the progeny was scored for GFP and RFP expression. The GFP-positive/RFP-negative F₃ progeny were either raised to adulthood for outcross or genomic DNA was harvested after stage 45 for molecular analyses. GFP: green fluorescent protein; RFP: red fluorescent protein.