ACTIVITIES OF GLYCOLIPID GLYCOSYLTRANSFERASES AND SIALIDASES DURING THE EARLY DEVELOPMENT OF XENOPUS-LAEVIS

The activities of glycosyltransferases and sialidases, together with t he ganglioside content and distribution, have been extensively studied in mammals, while the informations on tissues of other animals, inclu ding amphibian, are scarce. In this paper we present data on the activ ities of SAT-1, SAT-2, SAT-4, SAT-5, GlcNAcT-1, GalNAcT-1, GalT-6, and sialidases studied in Xenopus laevis embryos at different stages of d evelopment. The highest activity was found at days 4 and 5 of embryoge nesis for glycosyltransferases and sialidases respectively; a tentativ e correlation between the in vitro activity of these enzymes and the c ontent of neutral and acidic glycolipids is discussed.