Germ-line transmission of transgenes in Xenopus laevis

Adult Xenopus laevis frogs made transgenic by restriction enzyme-mediated integration were bred to test the feasibility of establishing lines of frogs that express transgenes. All of the 19 animals raised to sexual maturity generated progeny that expressed the transgene(s). The patterns and levels of expression of green fluorescent protein transgenes driven by a viral promoter, rat promoter, and four X. laevis promoters were all unaffected by passage through the germ line. These results demonstrate the ease of establishing transgenic lines in X. laevis.