Expression of HDGF family members in neural cell culture. Proteins extracted from cultured neurons, astrocytes, microglia, and oligodendrocytes were subjected to SDS-PAGE as described under material and methods. After blot transfer membrane was incubated with antibodies against the different HDGF family members or GAP-43 and actin as controls. Whereas HDGF is expressed to a similar extent in all four cell types, HRP-2 and HRP-3 show a more restricted expression pattern in neural cell cultures. Molecular weights of marker proteins in kiloDalton are given on the left.