CSH Protocols’ May Issue features a set of basic techniques for working with Xenopus laevis, the African Clawed Frog. While amphibians were used for experimental embryology as far back as the 1880’s, Xenopus became the amphibian of choice in the 1950’s, greatly aided by the work of John Gurdon…

A nice overview of Xenopus’ history as a model system can be found at the Wellcome Trust’s genome website. One of this month’s protocols explains how to induce ovulation in Xenopus females using Human Chorionic Gonadotropin. Back in the 1940’s and 1950’s this was the only reliable pregnancy test available–urine from a pregnant woman was injected into Xenopus females. If hCG was present, indicating pregnancy, the frog would ovulate. This resulted in many hospitals keeping colonies of Xenopus (which subsequently escaped, creating wild populations in many locations). The ready availablilty of Xenopus eggs, combined with their large size and amenability toward microsurgery and manipulation, led to their becoming a standard experimental system shortly thereafter.

In our May issue you’ll also find the basics of housing and keeping Xenopus in the lab, handling adults, dissection tools and methods, egg collection, isolation of testes, in vitro fertilization and techniques for dejellying and removing membranes from collected eggs. Many of these protocols were developed at Cold Spring Harbor Laboratory’s Xenopus course. Expect more Xenopus protocols over the next few months, including molecular techniques and embryonic manipulations.