Fucose-Containing Glycolipids Are Stage- and Region-Specific Antigens in Developing Embryonic Brain of Rodents

A monoclonal antibody (against 7A antigen), raised against a homogenate of embryonic rat forebrain, marks the distribution of region- and developmental stage-specific cell-surface antigens in the mammalian central nervous system. In the mouse, immunocytochemical staining revealed that 7A antigen is expressed almost exclusively in germinal layers of the cerebral cortex beginning as early as day 11 of gestation and becomes undetectable by birth. The typical staining is seen at embryonic days 13-15, in which only the ventricular and the subventricular zones of the cerebral cortex are intensely labeled, whereas most other areas of the brain are unlabeled. Tissue culture studies indicate that the 7A antigen is localized at the plasma membrane. Molecular species possessing the antigen are identified as neutral glycolipids that contain the X-determinant trisaccharide: [Note: Equation omitted. See the image of page 3045 for this equation.] This glycoconjugate is expressed in embryonic brains of many mammalian species (mouse, rat, rabbit, calf, and human) and may be a cell-surface component important in normal development of the central nervous system.