Fig. 5

EphA7 expression gradients are reduced in SC and dLGN of Ten-m3 KOs. A–D In situ hybridisation for EphA7 mRNA on whole mounts of SC from WT (A) and Ten-m3 KO (B) P0 mice. One lobe of the SC is shown. M medial; R rostral. In WTs high expression is apparent in the rostral SC (top of image) and decreases caudally. In Ten-m3 KOs EphA7 expression is much lower rostrally than in WT and a notably shallower gradient is present across the rostrocaudal axis. The dotted line denotes the borders of the SC. The midline is on the right side of the images. C Semi-quantitative analysis of all in situ hybridisation whole mount cases examined (n = 5–6 SCs each from three KOs and 3WTs). WT data show a linear high rostral to low caudal gradient (black trace). KO data (red trace) exhibit a much shallower gradient of expression with significantly lower values compared to WT across the most rostral 60% of the nucleus (univariate ANOVA, p < 0.001, interaction F(10, 99) = 6.789, p < 0.001; pairwise comparisons across each region of equal length show significant differences across the most rostral 60% of the nucleus). D Similar measurements obtained following in situ hybridisation of whole mounts SCs with an ephrinA5 probe. Whole mounts of SC reveal identical high-caudal to low rostral gradients of expression in Ten-m3 KOs as seen in WTs. ***p < 0.001; **p < 0.01; *p < 0.05. Scale bar: 250 μm, applies to A, B. E, F Whole mounts of SC stained using an ephrinA alkaline phosphatase affinity probe to reveal the binding activity of EphA receptors. In WTs (E), staining is darker rostrally (top of image) and diminishes more caudally. In KOs (F) expression is lower at the rostral end and largely uniform along the rostrocaudal axis. Dotted white line denotes borders of SC, solid line marks midline. Scale bar: 500 μm; applies to E, F. G–I Coronal sections through the dLGN at P0 following an in situ hybridisation reaction for EphA7 mRNA. In the WT (G) expression is high dorsally and reduced ventrally. Expression levels are dramatically reduced in KO (H) with very low levels of staining and no apparent gradient. The WT sense control (I) also shows low levels of staining. Dotted white line marks borders of dLGN. Dorsal is to the top and medial to the right of images. Scale bar: 100 μm; applies to G–I