IBCN   20355
INSTITUTO DE BIOLOGIA CELULAR Y NEUROCIENCIA "PROFESOR EDUARDO DE ROBERTIS"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Compartmentalization of the early blastula signaling center and its relationship with the precursors of the brain and the organizer
Autor/es:
LÓPEZ, SILVIA L.; ENCINAS, PAULA I; RODRÍGUEZ ABINAL, MATEO; CASTRO COLABIANCHI, AITANA MANUELA; BOYADJIÁN LÓPEZ, LAURA ELENA
Lugar:
Medellín
Reunión:
Congreso; IX Latin American Society for Developmental Biology (LASDB) Meeting; 2017
Institución organizadora:
Latin American Society for Developmental Biology
Resumen:
Compartmentalization of the early blastula signaling center and its relationship with the precursors of the brain and the organizerAitana M. Castro Colabianchi, Paula I. Encinas, Laura E. Boyadjián López, Mateo Rodríguez Abinal, Silvia L. LópezPresenting author: Aitana M. Castro Colabianchi. Corresponding author: Silvia L. LópezHilde Mangold grafted the dorsal blastopore lip of an amphibian gastrula on the ventral side of a host gastrula and obtained a secondary embryo. These properties lead the dorsal lip to be named as the Spemann-Mangold organizer. But before it is formed, an earlier dorsal center appears in the blastula, the BCNE Center, which expresses the BMP antagonists Chordin and Noggin. These, in turn, initiate brain neural induction earlier than it had been classically described. In Xenopus, this center is located in animal marginal-dorsal cells of the blastula and further gives rise to most of the brain and to all the endomesodermal tissues of the organizer. Moreover, it was also proposed that dorsal maternal ß-catenin triggers chordin expression in the BCNE while Nodal signaling is only required later to maintain chordin expression in the organizer.By performing functional experiments, we were able to demonstrate that early inhibition of the Nodal pathway by microinjection of either Cerberus-short or FAST1-SID mRNA completely abolished the expression of BCNE markers in the topographic region that would correspond to the future organizer, leaving their expression intact in more animal regions that would correspond to the prospective brain. These results are the first to indicate that the BCNE does not behave as a homogeneous territory but it is already compartmentalized into the precursors of the prospective brain (pre-brain) and the precursors of the organizer (pre-organizer), which can be distinguished earlier than previously thought and are being differentially regulated within this center. Contrary to what was previously proposed, both Nodal and ß-catenin signaling are required to trigger chordin expression in the pre-organizer domain within the BCNE, while chordin expression in the pre-brain requires ß-catenin but does not depend on Nodal signaling.Key-words: Nodal, BCNE center, organizer, chordin, brainUniversidad de Buenos Aires, CONICET, IBCN, Facultad de Medicina, Buenos Aires, Argentina