Triploid and gynogenetic diploid Xenopus laevis

Triploid and gynogenetic diploid Xenopus laevis frogs were produced using pressure to suppress the formation of the second polar body. Five to ten minutes after in vitro insemination, eggs were subjected to six minutes of hydrostatic pressure at 4,800 pounds per square inch. All of the surviving embryos tested were triploid. Application of the same pressure technique to eggs fertilized with ultraviolet irradiated sperm resulted in gynogenetic diploid embryos in every case where the sperm nucleus was inactivated. Triploid and gynogenetic diploid embryos developed normally through the larval period and metamorphosis.