Fig. 3: Semaphorin 7A Domains associated with membrane localization and dimerization are required for migration and axon outgrowth.
From: Semaphorin heterodimerization in cis regulates membrane targeting and neocortical wiring
a Schematic of Sema7A domains and deletion mutants. The scheme shows all currently annotated domains of Sema7A and depicts the deletion constructs generated. Sema domain is depicted in purple, the Plexin-Semaphorin-Integrin (PSI) domain in pink, the immunoglobulin domain (IG) in yellow and the Glycosyl-Phosphatidyl-Inositol (GPI) membrane anchor is depicted in orange. The Arginine-Glycine-Aspartic acid (RGD) reported to be important for Integrin binding was mutated to Lysine-Cysteine-Glutamic Acid (KCE) and is depicted as a red star. b Panoramas of Satb2fl/fl IUE brains with the indicated Sema7A deletion constructs together with pCAG-FSF-GFP and pNeuroD1-Cre and midline magnifications and quantifications. Full Length Sema7A panorama is reproduced here from Fig. 1 for comparison. Midline crossing is quantified as described in Fig. 1. Box and whisker plot whiskers as min-max with box bounds at lower and upper quartiles and center line on the median. Grey-ed out area at base of plot signifies measurements in this area are likely at the level of noise due to the complete absence of GFP fibers in Cre only condition (Fig. 1). Brown-Forsythe ANOVA with Dunnett’s T3 multiple comparisons test. padjusted Sema7A vs ΔSEMA = 0.0457, padjusted Sema7A vs ΔMEM = 0.0416, padjusted Sema7A vs KCE = 0.0342. nbrains Cre + Sema7A (from Fig. 1) = 8, nbrains Cre + Sema7A-ΔSEMA = 3, nbrains Cre + Sema7A-ΔPSI = 4, nbrains Cre + Sema7A-ΔIG = 4, nbrains Cre + Sema7A-ΔMEM = 6, nbrains Cre + Sema7A-KCE = 3. Scale bar in panoramic picture is 500 μm, while scale bar in midline magnification is 100 μm. c Sema7A deletion mutant migration profiles from E14-18 IUEs, presented in the same format described in Fig. 1. Cre + Full length Sema7A is reproduced here from Fig. 1 for comparison. Scalebar bottom left of Cre+Sema7A IUE is 100μm. (Right): Cell distributions for the different conditions are shown overlaid on the right with mean cortical position per nbrains, along with the mean of means ±SD. One way ANOVA with Dunnett’s multiple comparisons test. padjusted Sema7A vs ΔSEMA = 0.0001, padjusted Sema7A vs ΔMEM < 0.0001, padjusted Sema7A vs KCE = 0.0493. nbrains Cre + Sema7A (from Fig. 1) = 8, nbrains Cre + Sema7A-ΔSEMA = 3, nbrains Cre + Sema7A-ΔPSI = 4, nbrains Cre + Sema7A-ΔIG = 4, nbrains Cre + Sema7A-ΔMEM = 6, nbrains Cre + Sema7A-KCE = 4. For simplicity, panels denote p < 0.05 as *; p < 0.01 as **; and p < 0.001 as ***. All source data are provided in the Source Data file.
