Figure 1

Usp9x regulates polarity and adherens junction proteins in neural progenitors. (A) Coronal sections of E12.5 Usp9x ^+/Y and Usp9x ^−/Y neocortices stained for Usp9x, cell adhesion and polarity markers. Usp9x protein is expressed throughout the E12.5 Usp9x ^+/Y ventricular zone (VZ) (a) and depleted following Nestin-cre mediated deletion (b) (each image represents n = 3 Usp9x ^+/Y and Usp9x ^−/Y embryos). Immunoreactivity of the adherens junction-associated proteins N-cadherin (c,d) and AF-6 (e,f) as well as apical polarity markers aPKCλ (g,h), Par3 (i,j), Scribble (k,l) and Prominin1 (m,n) was reduced in Usp9x ^−/Y NPs compared to Usp9x ^+/Y NPs (n = 3). (B) Immunoblot analyses of total Usp9x, N-cadherin, AF-6 and aPKCλ protein levels in E12.5 Usp9x ^+/Y and Usp9x ^−/Y neocortices from n = 3 embryos each. (C) Quantification of protein levels in (B) relative to β-tubulin. (D) Coronal sections of E14.5 Usp9x ^+/Y and Usp9x ^−/Y neocortices stained with adhesion and polarity markers (n = 3). No difference was observed between Usp9x ^+/Y and Usp9x ^−/Y neocortices for the immunostaining pattern or intensity of N-cadherin (o,p), AF-6 (q,r), aPKCλ (s,t), Par3 (u,v) or Scribble (w,x). (E) Immunoblot analyses of neocortical lysates confirming depletion of Usp9x and restored N-cadherin, AF-6 and aPKCλ protein levels in E14.5 Usp9x ^−/Y brains. (F) Quantification of protein levels in (E) relative to β-tubulin. Scale bars = 80 μm. LV- lateral ventricle, VZ- ventricular zone. All data are shown as the means ± SEM. *p < 0.05.