astroglia in lower vertebrate optic nerves are unusual : as shown recently ( giordano et al. , 1989 ; rungger-brandle et al. , 1989 ) , they express abundant type ii cytokeratin , not glial fibrillary acidic protein ( gfap ) , the cytoskeletal marker for astrocytes elsewhere .
C0017626
glial fibrillary acidic protein
C0010853
cytoskeletal