The JONES monoclonal antibody has been immunocytochemically associated with regions of the developing rat brain where cell and axon migrations are occurring (Mendez-Otero et al., 1986, 1988). In the present study the antigens recognized by JONES antibody were analyzed in a variety of brain regions and at developmental ages selected to correspond to the preceding immunocytochemical observations. In accordance with earlier results from retina, JONES binding could not be detected in SDS gels from developing brain. Binding of the antibody was, however, prominent in chloroform/methanol extracts of the same tissues, and it was completely removed from tissue sections by brief chloroform/methanol treatment. Enzymatic analyses of chloroform/methanol extracts indicated that the JONES epitope was sensitive to neuraminidase but insensitive to proteases. Overlay assays on developed high-performance thin-layer chromatographic plates (HPTLC) indicate that in all regions the JONES epitope resides on 2 or 3 ganglioside bands, depending on the age examined. These bands migrate between ganglioside standards GD1a and GM2 on HPTLC plates and have been designated GJ1, GJ2, and GJ3, with the higher number designating the more rapidly migating species. Occasionally, additional bands migrating in the range of polysialogangliosides were observed. The pattern of expression of GJ species was studied in forebrain, retina, and cerebellar tissue taken from embryonic day 18 (E18), postnatal day 0 (P0), P7, P14, and adult animals. Both region-specific differences in the relative prominence of each band and stage-specific differences in the total amount of the JONES gangliosides were detected. The stage-specific differences in the amount of JONES antigens are well correlated with the developmental periods of maximal cell migration in each region. While the JONES gangliosides are most prominent in forebrain before birth, in retina they are most prominent during the first 2 postnatal weeks. In cerebellum, JONES antigen expression is more pronounced during the 2 periods of cell migration in this tissue. In retina, the more rapidly migrating GJ3 band was the most prominent band at all stages examined, and this same band is retained in the adult. In cerebellum and forebrain CJ3 is also the most pronounced band during development. However, in contrast to the retina, the more slowly migrating GJ1 band is retained in adult forebrain and cerebellum. A variety of non-brain tissues have also been examined for the presence of the JONES antigens. The GJ1 and GJ3 bands are prominent in E18 dorsal root ganglia, and dot assays reveal their presence in chloroform/methanol extracts of P2 and adult kidney and P2 adrenal glands. The same assays failed to reveal any JONES antigenicity in P2 thymus, lung, heart, stomach, spleen, liver, intestine, and skeletal muscle. Our results indicate that JONES antibody recognizes a sialic acid-bearing carbohydrate epitope on a small subset of gangliosides in all brain regions examined. In the developing brain the biochemical localization is fully consistent with a role for these antigens in selective cell motility. The biochemical differences in JONES binding in the adult as well as the presence of the antigens in kidney cautions, however, that these same molecules may be associated with quite different functions in non-neural regions or in the adult brain.
|Original language||English (US)|
|Number of pages||13|
|Journal||Journal of Neuroscience|
|State||Published - 1988|
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