Antibody Uptake Assay in the Embryonic Zebrafish Forebrain to Study Notch Signaling Dynamics in Neural Progenitor Cells In Vivo.

Stem cells can generate cell fate heterogeneity through asymmetric cell division (ACD). ACD derives from the asymmetric segregation of fate-determining molecules and/or organelles in the dividing cell. Radial glia in the embryonic zebrafish forebrain are an excellent model for studying the molecular mechanisms regulating ACD of stem cells in vertebrates, especially for live imaging concerning in vivo molecular and cellular dynamics. Due to the current difficulty in expressing fluorescent reporter-tagged proteins at physiological levels in zebrafish for live imaging, we have developed an antibody uptake assay to label proteins in live embryonic zebrafish forebrain with high specificity. DeltaD is a transmembrane ligand in Notch signaling pathway in the context of ACD of radial glia in zebrafish. By using this assay, we have successfully observed the in vivo dynamics of DeltaD for studying ACD of radial glia in the embryonic zebrafish forebrain.