Copyright © 2005 Burlibaşa, Cucu, Gavrilă.
Published by: Portuguese Wildlife Society
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Creative Commons Attribution 2.5 Portugal License

• L. Burlibaşa *
  University of Bucharest, Institute of Genetics 1-3 Aleea Portocalelor, Sector 6, Bucharest, Romania Tel/Fax: + 4021 318 15 65
• N. Cucu *
  University of Bucharest, Institute of Genetics 1-3 Aleea Portocalelor, Sector 6, Bucharest, Romania Tel/Fax: + 4021 318 15 65
• L. Gavrilă *
  University of Bucharest, Institute of Genetics 1-3 Aleea Portocalelor, Sector 6, Bucharest, Romania Tel/Fax: + 4021 318 15 65

Abstract

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.
Keywords: amphibians, chromatin remodelling, gametogenesis, DNA methylation, lampbrush chromosomes, ribosomal gene amplification.

Keywords: amphibians; chromatin remodelling; gametogenesis; DNA methylation; lampbrush chromosomes; ribosomal gene amplification.