Central nervous system antigen (NS-5) and its presence during murine ontogenesis

An antiserum raised by immunization of C3H.SW/Sn mice with cerebellum from 4 day old C57BL/6J mice recognizes a cell surface component(s) [NS 5] present in different degrees on various parts of the mouse central nervous system. When analyzed by an antiserum and complement mediated cell cytotoxicity test and by the ability of various tissues to absorb anti NS 5 antiserum activity, the antigen(s) was detectable on cerebellum, retina, olfactory bulb, cortex, basal ganglia, and medulla, but not on nonneural tissues with the exception of mature spermatozoa and 4 day old kidney. The antigen(s) detected by the anti NS 5 antiserum was found in similar quantities on young and adult rat and mouse cerebellum; however, it was not detectable on any of 16 clonal cell lines derived from the rat central nervous system. During preimplantation stages of murine development, the antigen could be detected on all cells of (2 to 4) cell and (8 to 16) cell stages and on the trophoblastic cells of blastocysts by indirect immunofluorescence. Embryos on day 9 of gestation, the earliest stage tested after implantation, expessed the antigen(s), but expression was restricted to the nervous system.