A monoclonal antibody that defines rostrocaudal gradients in the mammalian nervous system

Spinal cord axons display a rostrocaudal, positional bias in their innervation of sympathetic ganglia and intercostal skeletal muscles. In an effort to examine the molecular basis of this positional specificity, we used the cyclophosphamide immunosuppression method to produce monoclonal antibodies that bind preferentially to rostral ganglia. The staining distribution of one of these antibodies, ROCA1, has been analyzed using a novel histological method. A graded decline in binding is observed along the chain of adult rat sympathetic ganglia, as well as in the nerves innervating intercostal muscles. The antigen is identified on immunoblots as a 65 kd protein, whose distribution corresponds to the pattern found histologically. Surprisingly, ROCA1 appears to bind to glial cells, implying rostrocaudal, molecular differences in their surfaces.