Amphibians are anamniotic vertebrates having conquered the terrestrial environment. Their reproduction and development occur in water. After metamorphosis, the animal leaves the water to live on the ground. Yet, some species remain in the water and certain of them are viviparous. Since a long time, amphibians are used such as animal models to understand physiological or developmental mechanisms. Today, amphibians can be used such as excellent models to understand the importance of cell proliferation, differentiation and death throughout embryonic development. A second way concerns the importance of these phenomena in the organs subjected to very sharp variations, alternation of differentiation/dedifferentiation throughout the sexual cycle, according to external or experimental conditions. The importance of apoptosis and of the presence of calpains has been noted throughout embryonic development of Xenopus laevis. In several caecilians, the spectacular variations of oviducts throughout the sexual cycle are linked to seasonal alternations, and under the control of several hormones and their receptors.
In this review, an overview of works performed by our laboratory is given. The models used were the anuran Xenopus laevis in order to study the apoptosis from fertilization to metamorphosis and several caecilian amphibian species in order to understand the interactions of these phenomena during the alternation of differentiation/ dedifferentiation of the oviducts throughout the sexual cycle.