Abstract: | A new DNA ligase activity is expressed when the Axolotl eggs enter cleavage. The messenger RNA can be labelled by [3H] uridine thereby indicating its de novo synthesis. This new genetic expression is occurring just before cleavage and is the earliest found during Amphibian development. The newly synthesized [3H] mRNA can be translated in vitro in the rabbit reticulocyte lysate system. The resulting product is a 160 K protein specifically immunoprecipitated with the antiserum directed against 8S DNA ligase. This in vitro translated polypeptide exhibits 8S DNA ligase activity specific of activated or fertilized eggs but does not display 6S DNA ligase activity of non activated eggs. |