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Africa's unique frogs: Hidden helpers in obstetrics research


From the 1930s to the 1960s, obstetric examinations often required a slippery instrument: the African clawed frog. Hospitals and research institutes worldwide rely on these amphibians as a valuable resource for scientific and obstetric research. But what makes these frogs so special?


Unlike what we often imagine, these frogs do not have the ability to jump around and catch insects with their long tongues. Most of their lives are spent in the water, as they are more adapted to swimming than jumping or jumping. Interestingly, African clawed frogs do not have tongues. Instead, they feed by swallowing food directly into their mouths or using their powerful claws to catch larger prey and tear them to pieces.


The smooth skin of these frogs can change color to blend in with their surroundings, enhancing camouflage and approaching prey without being detected. This remarkable camouflage ability attracted the attention of three biologists in South Africa during the 1920s: Hillel Shapiro, Harry Zwarenstein, and their teacher Lancelot Hogben. They studied the role of the pituitary gland, a small area in the frog's brain, in the mechanism of color change. When the pituitary gland is removed, the frog's camouflage ability is reduced. However, when Hogben injected frogs with extracts from a cow's pituitary gland, he made a surprising discovery: they began to lay eggs without a mate. Normally, female African clawed frogs only lay eggs when there is a male nearby to mate. But cow hormones stimulate ovulation, eliminating the need for a male. This discovery sparked an idea for the researchers.