1988 Volume 104 Issue 6 Pages 973-979
We have established many mouse monoclonal antibodies detecting developmentally regulated antigens in chicken embryonic neural tissues of the otic vesicles and neural tube by immunizing mice with the membrane fraction of the neural tube and somite prepared from 3-d chick embryos. Among them, three monoclonal antibodies (MAbs) M6703, M6704, and M7103 were shown to react with the gangliosides isolated from chicken embryonic brains. The precise specificity of the antibodies was determined mainly by enzyme-immunostaining on thin layer plates. MAbs M6703 and M6704 bound to C-series polysialogangliosides including GT3, GT2, GT1c, GQ1c, and GP1c isolated from cod fish brains, but never to A-series, B-series, or X-series gangliosides. On the other hand, MAb M7103 antibody has a rather narrow specificity, reacting with GT1c, GQ1c, and GP1c, but not with ganglioside GT3. This indicates that the epitopes defined by these two MAbs are different from each other. MAbs M6703 and M6704 recognize a trisialosyl residue, NeuAca 2-8NeuAcα2-8NeuAcα2-3, while M7103 requires both a trisialosyl residue and the gan-gliotetraosy backbone structure for binding. As compared to similar MAbs which have been reported in the literature. M6703 and M6704 are unique in that they react equally with all of the C-series gangliosides and belong to the IgG3 subclass. Using these two MAbs, the developmental changes of C-series gangliosides in chicken optic lobes during enceph-alogenesis have been demonstrated quantitatively. GT1c, GQ1c, and GP1c reached the highest level during the embryonic days 12-14, and GT3 was highly enriched at the 10th day and then gradually decreased. Very small amounts of GT3, GT1c, and GQ1c were still found in adult chick brains. These findings suggest that unusual C-series gangliosides on neural
cell surface membranes may be involved in the process of encephalogenesis.
