Three-dimensional anatomical atlas of the African clawed frog

A three-dimensional anatomical atlas of the model organism Xenopus laevis (African clawed frog) is now available, helping researchers to understand embryonic development and metamorphosis – the fascinating process by which a tadpole transforms into an adult frog.

Xenopus laevis, the African clawed frog, is a well-studied and versatile model organism for developmental biology. The extensive data base ranges from classical transplantation experiments from the early 20th century to modern studies with high quality genome sequencing. However, there has been a gap in the availability of comprehensive datasets covering the late developmental stages of this frog.

A research team led by Dr. Jakub Harnos from Masaryk University in the Czech Republic has now closed this gap. The frogs used the 3D imaging technique of X-ray microtomography to create a detailed anatomical atlas. This new resource makes it possible to precisely describe the different developmental stages of Xenopus laevis and accurately track the anatomical changes during metamorphosis from the tadpole stage to the adult frog.

One of the most remarkable examples of the detailed tracking of anatomical changes is the positioning of the eyes of the developing frog. During development, the distance between the eyes decreases, which is related to the frog’s lifestyle: from an aquatic tadpole with eyes positioned on the side to an adult frog with eyes positioned on the head for a subaquatic lifestyle, similar to crocodiles.

The frog’s gut also undergoes a significant transformation during metamorphosis. Within eight days, the intestine shortens by about 75% and the winding pattern changes drastically. These processes, which are difficult to examine using other methods, can now be studied in detail thanks to X-ray microtomography.

In addition to these anatomical details, sex-specific differences and the fine positioning of the teeth of Xenopus laevis can also be examined.

“Our study provides all X-ray microtomography data openly, allowing other researchers to investigate both soft and hard tissues in unprecedented detail in this key vertebrate model,” Dr. Harnos emphasizes.

To facilitate access to this data, the team has made a collection of 40 3D models available on the Thingiverse design platform. These models can be downloaded and printed to illustrate the research results. The digital models are also available on the Sketchfab platform and can be viewed as part of the published research.

These advances in 3D printing and 3D imaging are making a significant contribution to making science more accessible and understandable, while enabling new insights into developmental biology.