Amphibians as Model Organisms for Studying the Dynamics of Eukaryote Genetic Material Architecture

Amphibians have played a key role in the elucidation of the mechanisms of early development over the last century. Much of our knowledge about the mechanisms of vertebrate early development comes from studies using Xenopus laevis. Xenopus sp. is a major contributor to our understanding of cell biological and biochemical processes, including: (1) chromosome replication; (2) chromatin, cytoskeleton and nuclear assembly; (3) cell cycle progression and (4) intracellular signaling. Amphibian embryos remained the embryos of choice for experimental embryology for many decades. European embryologists used predominantly urodele embryos (such as Triturus) and embryos of the frog Rana temporaria, which is related to the North American species Rana pipiens. Using light, fluorescence, transmission electron microscopy (TEM) and molecular investigations, some peculiar aspects of chromatin and chromosome organization and evolution in oogenesis and spermatogenesis of amphibians were investigated. We have focused our investigations on dynamics of the chromatin structure in different stages of development.