antibody (1:1000, BD Pharmingen, San Diego, CA) at 4°C overnight. β-actin (Sigma Chemical, St. Louis, MO) was used as an internal control. This antibody produces a single band at approximately ~185 kDa on Western blots consistent with the predicted weight of DCC. The specificity of this antibody has been validated previously using embryonic tissues from Dcc knockout and Dcc wild type embryos [55]. The band intensity was quantified using National Institutes of Health image J analysis software (version 1.44, Bethesda, MD).
