(A to C) Zeb2 represses neuronal adhesion. (A) Surface proteins on Zeb2fl/fl NexCre and Zeb2fl/fl cortical neurons prepared from E15.5 embryos were identified by biotin-linked mass spectrometry. DIV, days in vitro. (B) Top Gene Ontology (GO) terms for surface proteins up-regulated ≥1.5× upon loss of Zeb2. ECM, extracellular matrix; KEGG, Kyoto Encyclopedia of Genes and Genomes. (C) GO of surface-expressed proteins. Red nodes are up-regulated in Zeb2fl/fl NexCre and blue nodes are up-regulated in Zeb2fl/fl animals. ATPase, adenosine triphosphatase; MAPK, mitogen-activated protein kinase; RTK, receptor tyrosine kinase. (D and E) Zeb2 suppresses neuronal aggregation. (D) Aggregation of single-cell suspensions over time. Scale bars, 100 μm. (E) Average cell aggregate size. N = 15, 10, and 7 Zeb2fl/fl and 12, 12, and 15 Zeb2fl/fl NexCre aggregates at 0, 30, and 60 min, respectively. One-way ANOVA with Kruskal-Wallis test. (F and G) Zeb2 inhibits adhesion to the extracellular matrix. (F) Attachment of neuronal suspensions to laminin-coated surfaces after 2 hours. Scale bars, 15 μm. (G) Lamellipodial spreading of attached cells. N = 42 Zeb2fl/fl and 56 Zeb2fl/fl NexCre cells. Mann-Whitney test. (H to J) Zeb2 regulates radial migration through suppression of integrin signaling. (H) IUE of GFP and ItgB1DN into Zeb2fl/fl and Zeb2fl/fl NexCre E14.5 littermate animals. (I) GFP+ neurons at E18.5. Scale bar, 100 μm. (J) Laminar distribution of GFP+ neurons. N = 12 Zeb2fl/fl, 5 Zeb2fl/fl NexCre, and 5 Zeb2fl/fl NexCre + ItgB1DN animals. Two-way ANOVA with Bonferroni post hoc test.