GENETIC-CONTROL OF DEVELOPMENT IN XENOPUS-LAEVIS

In this paper we address the question of how genes can control develop ment by using Xenopus as a model system, since it combines the classic al advantages of amphibian embryology with advanced molecular techniqu es. Several developmental regulator genes have been shown to encode fo r transcription factors which trigger the activation of downstream gen es, thus resulting in a cascade of regulatory events. In the first two examples, we deal with regulatory events that underlie early body pat terning in vertebrates, and with the role of homeobox transcription fa ctors in deciphering positional information along the body axis. In th e third example, we address the question of the role of post-transcrip tional regulation in development by studying the possible regulatory r ole of a cytoplasmic zinc finger protein, presumably acting through RN A-protein interactions. The general idea is that understanding how gen es can control development will hopefully lead to understanding the co nstruction of a shape, and eventually of an organism.