Immunohistochemical and fluorescence stains were performed on 5 um, paraffin-embedded sections from E13.5, E15.5, P0, and adult wildtype and conditional Exoc5 mice as previously described11 (link). Antibodies and their dilutions include: acetylated tubulin (Sigma, #T6793, 1:500), gamma tubulin (Abcam, #T6793, 1:1000), RUNX2 (Abcam, #ab192256, 1:250), ERK1/2 (Cell Signaling, #4695, 1:50), phospho-ERK1/2 (Cell Signaling, #4370, 1:40), cleaved NOTCH1 (Cell Signaling, #4147, 1:200), Hoescht (Life Technologies, #H3569, 1:10,000), and Life Technologies Alexa Fluors: 488 (#A-11029, #A-11034) 568 (#A-11004, #A-11036) and Cy5 (#A-10524) at 1:100. Slides were coverslipped using Invitrogen SlowFade Gold Antifade Reagent (#S36936). Images were captured using: Leica TCS SP5 AOBS Confocal Microscope System and LAS AF v2.6.3 Build 8173 Acquisition and Analysis Software, Zeiss Axioscope M2, or Olympus BH-2 brightfield microscope.