Transgenesis in Xenopus tropicalis. The synthetic transposase mRNA and a transposon donor plasmid containing a Tol2 construct with a ubiquitous promoter and the gene encoding green fluorescent protein (GFP) are co-injected into X. tropicalis fertilized eggs. The Tol2 construct is excised from the donor plasmid  and integrated into the genome. In the study conducted by Hamlet and coworkers , injected GFP-positive tadpoles were raised to adulthood. Tol2 insertions created in germ cells are transmitted to the F1 generation. Germ cells of the injected frogs are mosaic, and, by crossing theinjected frog (founder) with wild-type frog, nontransgenic tadpoles and transgenic tadpoles heterozygous for the Tol2 insertion are obtained .