24. Sept. 2024

The frog Xenopus laevis serves as a key model organism in the field of developmental biology. Its easily accessible embryonic development and relatively long life cycle make it an ideal candidate for genetic studies.

The collaboration of our scientists from the Laboratory of X-ray micro and nano computed tomography at CEITEC BUT with Dr. Harnoš from Masaryk University has been a significant contribution to the research of Xenopus laevis. This collaboration enabled detailed mapping of the individual developmental stages of this frog – from tadpole to adult. Using the micro-CT method, it was possible to create a 3D atlas that captures not only the external form of the frog, but also provides detailed insight into internal structures such as bones, muscles and organs.

X-ray computed microtomography (micro-CT) has brought a new dimension to the study of this animal. Unlike earlier microscopy-based research methods, micro-CT allows the entire body to be digitized in 3D at high resolution. However, in order to image soft tissues, samples had to be chemically altered to increase the contrast between hard and soft tissues using heavy metals. Therefore, each sample had to be scanned twice – once to view the hard tissues (bones, teeth) and a second time to view the soft tissues.

One of the most interesting periods of Xenopus development is the metamorphosis phase, when major changes in body structure and size occur. Prior to metamorphosis, the tadpole gradually grows and accumulates body mass, which it then uses as an energy source for the development of new organs. During this process, for example, the gills and tail disappear while the lungs and limbs, which are crucial to the life of an adult frog, develop. Micro-CT has made it possible to observe changes in these structures in the early stages of metamorphosis, when their overall size is only a few millimetres.

The aim of the project was not only to describe the morphological changes during Xenopus development, but also to provide the community of developmental biologists with access to digitized data of each developmental stage. These data allow any structure to be examined in detail, both visually and quantitatively. 3D models allow changes between stages to be tracked and differences between males and females, for example, to be analysed, with males tending to be about a third smaller than females.

Despite the high resolution and detail that micro-CT provides, it has its limitations. One of the main limitations is the need for double scanning to both image soft and hard tissues. However, this technique provides a previously unseen view of Xenopus development in 3D and opens up the possibility of further exploring its morphological and genetic properties.


More information can be found in the study: Unveiling vertebrate development dynamics in frog Xenopus laevis using micro-CT imaging