Unusual hybrid – Live pregnancy test – Spawn as a huge model cell – Closer to human! – Artificial mini-organism

“Xenopus” is a genus of frogs that includes several species, but this term is most commonly associated with two main types: Xenopus laevis and Xenopus tropicalis.

Here is a brief description of each:Xenopus laevis:Also known as the African Clawed Frog.Inhabits various water bodies in Africa, including temporary water bodies and rivers.Some frog species, such as the clawed frogs (genus Xenopus), have a less developed tongue compared to other species. This is due to their unique anatomy and adaptation to a specific lifestyle.

In Nature: The color palette of Xenopus frogs in the wild can vary, but it often includes subdued shades that blend with the surrounding environment. Species like Xenopus laevis may have greenish-brown hues, helping them effectively camouflage among algae and substrate.

Reproduction:
Xenopus levis follows an interesting reproductive strategy. During the rainy season, males vocalize to attract females. The courtship culminates in the female laying eggs, which the male fertilizes externally. The eggs hatch into tadpoles, undergoing metamorphosis into juvenile toads.

Bred by Aquarium Enthusiasts:

Aquarists breeding Xenopus in captivity can develop diverse colors uncommon in nature. These may include bright shades like orange, yellow, or red, as well as various combinations of color morphs. These altered colors enhance the frogs’ aesthetic appeal, making them intriguing for aquarium enthusiasts. I really love watching the clawed frog, especially when it eats. Due to her underdeveloped tongue, she is unable to use it while feeding, so she cutely grabs food with her front paws, making her look like a little monkey. The frog has characteristic spurs on its hind legs, which are well developed in males, what gave them that name “Spurred frog“. These frogs are predatory and try to put in their mouths everything that can fit there, so it is a bad idea to put fish in the aquarium with them.

Scientific interest

Used in scientific research, including developmental biology, genetics, and medicine.Widely employed in laboratory studies due to their relative ease of care and lack of complex housing requirements.

Until the 60s of the 20th century, toads were used to test for vaginess. In 1930, the British biologist Lancelot Hogben discovered that when a male African clawed toad hatches from a female womb, the toad releases eggs within 5 to 12 years.

The test on toads will be simple, safe for the toad and reliable. Until then, the bear was burrowed into an immature female mouse, and after a few days the bear was beaten and opened to check that its ovaries had not swelled. In a later version of the test, rabbits were used instead of mice. At one station for diagnosing vaginosis, approximately 6,000 rabbits were sacrificed per river.

The amphibian egg is a large cell. And in general, oocytes are one of the largest known cells. The egg cell of a smooth clawed frog reaches more than 1 mm in diameter (can be seen with the naked eye!), and its nucleus is 100,000 times larger than the nucleus of a normal cell. Therefore, in terms of ease of manipulation, they can compete with the giant axons of the loligo squid, which we wrote about in our June article [6]. As with loligo axons, the functioning of ion channels can be studied on them. And there is one advantage. Using squid axons, you can only study the work of those channels that are already in their membrane! It is almost impossible to force a squid neuron to express a channel that is not characteristic of it on its axons. But a xenopus egg is possible! By injecting the necessary messenger RNA into it, you can get a large model cell, the membrane of which contains ion channels from the human heart, the brain of a guinea pig, or, say, the kidneys of an Egyptian flying dog. This giant cell is convenient for measuring changes in membrane potential in response to various influences – say, the addition of a drug.

In addition, from a large number of xenopus eggs, you can prepare a cell-free mixture (it would be more correct to say: “cell-free system”), which can transcribe genes in a test tube, synthesize proteins from a given mRNA, perform post-translational modification of proteins and many other useful things. A biochemist’s dream – they also have something to love about the xenopus! For transcription in vitro, an extract is made from the nuclei, and for translation and post-translational modifications, an extract is made from the cytoplasm. Fortunately, the cell is large and there is a lot of cytoplasm.

Xenopus tropicalis:

A species of clawed frogs found in the western part of Central Africa.Possesses a more compact genome and a shorter developmental period, making it an attractive subject for research.Widely used in studies related to genetics, developmental biology, and understanding tissue healing mechanisms.Both Xenopus species are important subjects for scientific research and are frequently used to study various aspects of biology and medicine.

John K. Barrows, David T. Long. (2019). Cell-free transcription in Xenopus egg extract. J. Biol. Chem.. 294, 19645-19654;

Glenn Matthews, Alan Colman. (1991). A highly efficient, cell-free translation/translocation system prepared fromXenopuseggs. Nucl Acids Res. 19, 6405-6412;

John B. Wallingford, Karen J. Liu, Yixian Zheng. (2010). Xenopus. Current Biology. 20, R263-R264;