Fig. 1

Comparison of ganglioside expression and localisation in wild type and novel GalNAcT^−/−(Tg-neuronal) mice that exclusively express complex gangliosides in neurons. a Enzyme activity assays showed a restoration of GalNAcT activity to ~50 % in 2 different GalNAcT ^−/− -Tg(neuronal) lines compared to wild type (n = 3/genotype). The dashed line represents the threshold level of activity for the assay therefore GalNAcT ^−/− falls below this and is essentially zero despite minimal value. b Ganglioside biosynthetic pathway. The GalNAcT enzyme is necessary for generation of complex gangliosides (surrounded by the green box). c Brain extracts from wild type, GalNAcT ^−/− and 2 strains of GalNAcT ^−/− -Tg(neuronal) were probed with anti-GM1 IgG antibody, DG2. This antibody bound all genotype extracts except for GalNAcT ^−/− which lack complex gangliosides including GM1. GM1 lipid was printed on the left and provided a positive control for anti-GM1 antibody binding. d Axonal binding can be observed in the GalNAcT ^−/− -Tg(neuronal) mice treated with anti-GM1 antibody (arrows), while it bound to the terminal kranocyte (asterisk) in wild type mice and was absent in GalNAcT^−/− tissue. Anti-GQ1b/GD3 antibody bound similarly in both strains along the axons and on the perisynaptic Schwann cell membranes (arrowheads) that are simple ganglioside GD3 positive. Scale bar = 10 μm