Fig. 7. Injection of soluble PSA causes the same defects in the growth pattern of commissural axons in the hindbrain as does removal of PSA. (A,B) Hindbrain of zebrafish embryos at 36 hpf in an overlay of interference contrast and DiI fluorescence (asterisks mark DiI injection sites). (A) In sialic acid trimer-injected embryos, DiI-labelled commissural axons cross the midline and reach the contralateral side. (B) Hindbrain of a soluble-PSA injected embryo. The commissural axons fail to reach the other side and stop at the midline. oto, otocyst. Scale bar: 50 µm. (C) Quantification of the effects on the growth pattern of hindbrain commissural axons caused by the injection of control-buffer, endo N, PSA-polymer and PSA-trimer.
