Mitani S, Okamoto H
Department of Neurobiology, Faculty of Medicine, University of Tokyo, Japan.
Neuroscience. 1988 Apr;25(1):291-305. doi: 10.1016/0306-4522(88)90027-9.
Monoclonal antibodies were raised against larval tissues from Xenopus laevis. Two of them which bound to neural tissue were examined for their cytological specificities by indirect immunofluorescence on larval frozen sections. One of the monoclonal antibodies (NM1) had affinity for both neural and muscular tissues, while the other (N1) bound exclusively to neural tissue. NM1 was shown in the neural tissue to possess a high affinity for the axons from a large population of neurons and possibly the radial fibers from ependymal cells as well. On the other hand, N1 showed a high specificity for some cellular elements other than axons in the white matter, most likely dendrites. For both antibodies, binding to cell bodies could not be detected. The spatial and temporal distribution of the NM1 and N1 antigens was investigated. In the mid-trunk region the NM1 antigen in axons was first detected at stage 29/30, nearly 10 h earlier than the N1 antigen (stage 33/34). In a larva at stage 37/38, the axonal NM1 antigen was distributed throughout the nervous system, whereas the distribution of N1 antigen was restricted to the brainstem and the trunk spinal cord. The N1 antigen-positive area continued expanding rostrocaudally with increasing developmental age. The distribution of NM1 and N1 antigens, thus, follows patterns which are consistent with the previously shown general patterns of neuronal process development; the earlier outgrowth of axons than dendrites, and the rostrocaudal gradient in process development. We also examined the two monoclonal antibodies in a cell culture system derived from hatching larvae and found that cytological specificity was substantially conserved; NM1 possessed affinity for both neuronal and muscular cells and N1 bound exclusively to neuronal cells, though N1 bound to cell bodies as well as processes in culture.
