Fig. 5.

Fig. 5.

The content of multiple GAGs is altered globally and locally reduced in chondrocytes of galns^m/m mutant larvae. (A,B) Mass spectrometry-based analyses of global GAG content in whole wild-type and galns^m/m mutant larvae at 6 dpf (A) and 10 dpf (B) show slight, albeit insignificant, differences in chondroitin sulfate (CS) and dermatan sulfate (DS) at 6 dpf that are, by 10 dpf, matched by changes in heparan sulfate (HS) and keratan sulfate (KS). (C) Confocal images of immunohistochemically analyzed cartilage sections from fli1a:EGFP-positive larvae show that heparan sulfate levels (red) are locally decreased in mutant larvae as early as 4 dpf. WGA, blue. Scale bar: 10 µm. (D) Similar analyses of chondroitin sulfate (red) also showed local alterations in mutant cartilages, including lower levels of cell surface chondroitin sulfate that are matched by increased intracellular staining. This was evident in both the ceratohyal and Meckel's cartilages. Arrowheads show regions of cell surface CS staining in wild-type larvae, but intracellular CS in mutant larvae. Scale bar: 10 µm.