African Clawed Frog

The African clawed frog (Xenopus laevis) is an aquatic frog of southern Africa that became one of the workhorses of developmental biology and cell biology. Its large eggs can be injected, manipulated and observed easily.

🧬 Field Guide Specimen: Open African Clawed Frog in the CRV Science Field Guide to log the specimen, see its place among the Tetrapoda lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.

In 1962 John Gurdon replaced the nucleus of a frog egg with a nucleus from a tadpole's intestinal cell and obtained normal tadpoles. This demonstrated that a differentiated cell retains all the genetic information needed for development, a result for which he shared the 2012 Nobel Prize with Shinya Yamanaka. See Cellular differentiation.

In the 1930s Lancelot Hogben found that injecting a woman's urine into a female frog made her lay eggs within hours if the woman was pregnant, because of the hormone hCG. The frog was used in pregnancy tests for decades and spread around the world through the trade.

The frog's genome is allotetraploid, with two sets of ancestral chromosomes. Escaped animals have established invasive populations, and the species can carry the chytrid fungus that has devastated amphibians worldwide.

• Stem cell biology and regenerative medicine — reprogramming of nuclei
• Embryogenesis — early development