A model for the regulation of epiblast cell–BM interaction by CLASP and DG-mediated cortical anchoring of basal MTs during gastrulation EMT. In epiblast cells before undergoing gastrulation EMT, basal MTs are anchored to and stabilized at the basal cortex through the CLASP–LL5 complex. DG is distributed at the lateral and basal cell membrane, and its basal localization is dependent on basal MT stability and its interaction with the CLASP–LL5 complex. Basal cortical localization of LL5s is largely MT independent, and its interaction with basal membrane proteins like DG and integrins (not depicted) awaits further clarification. It is hypothesized that LL5 basal localization helps enrich and stabilize basal CLASPs and consequently basal MTs. This positive regulatory loop is disrupted as epiblast cells move toward the streak midline, resulting in the loss of basal membrane–BM interaction and consequently BM breakdown.