The expression of the intermediate filament-associated protein (NAPA-73) is associated with the stage of terminal differentiation of chick brain neurons

Abstract

The monoclonal antibody E/C8 was originally generated against chicken dorsal root ganglia. The antigen detected by E/C8, NAPA-73, is an intermediate filament-associated protein. NAPA-73 was shown to be one of the earliest neuronal markers to appear during development since it appears in some neuronal precursor cells of the peripheral nervous system during development. Using [³H]thymidine pulse-chase experiments combined with immunocytochemistry, ut is shown that the dividing neuroblasts from 6-day-old embryonic chick brains do not express NAPA-73. Only neurons that have undergone their terminal cell division either in the embryo or in cell culture express the E/C8 immunoreactivity. We conclude that E/C8 is a marker for postmitotic neurons in chick brain. The contrast between our findings and previous reports identifying NAPA-73 as one of the earliest neuronal markers may reflect a difference between the central and peripheral nervous systems.