Fig. 3. Aqueduct of Sylvius and SCO in wild-type and transgenic mice. (A) Coronal sections in a rostral (r) to caudal (c) direction from P0.5 wild-type and transgenic littermates stained with Hematoxylin and Eosin, demonstrating the apparent absence of the SCO in the transgenic mouse. (B) Similar sections stained with an antibody to Reissner's fibers. Note the near-absence of antibody staining in the transgenic section (top) compared with the wild-type section (bottom). The arrow in the top section indicates a small amount of antibody staining in one section from the knockout mouse, indicating the presence of the Reissner's fiber antigen. The counterstain was Hematoxylin. Scale bar in B: 50 µm (bottom); 20 µm (top).