Effects of PPMP in Xenopus laevis early embryogenesis

MELCHOR E. LUQUE; MARÍA E. MÓNACO; MANUEL J. AYBAR; SARA S. SÁNCHEZ

Los Cocos, Córdoba

Workshop; International Workshop “Latest concepts in Developmental Biology”; 2006

Glycosphingolipids (GSL) are believed to be important for the dynamics of many cell membrana events, including cellular interactions, signalling and trafficking. PPMP (DL-threo-1-Phenyl-2-palmitoyl-amino-3-morpholino-1-propanol) is a potent and specific inhibitor of the synthesis of GSL, and is a useful tool for the study of the involvement of GSL in many developmental processes. In previous studies we investigated the ganglioside profile, cellular expression, and biosynthesis during the early development of the Bufo arenarum amphibian embryo. In addition, the spatio temporal expression patterns of two key enzymes (glucosylceramide synthase and GD3 synthase) were determined. In this work we report the effect of PPMP in morphogenetic movements during Xenopus laevis gastrulation. In vivo and in vitro experiments, using resin microspheres soaked in PPMP were performed. They were implanted in the right side of stage 10 embryos and in standard Keller explants. In order to examine if the morphogenetic movements of gastrulation were affected specific markers for the mesoderm (brachyury, goosecoid, chordin) and neuronal tissues (Sox2) were analysed. We propose that the convergent extension defects caused by GSL biosynthesis inhibition alter the correct localization, but not the expression, of mesodermal and neural markers.