Tooth epithelium and mesenchyme (IMAGE) University of California - Santa Barbara Caption Tooth epithelium (cell surface; yellow) and mesenchyme (cell surface; magenta). Proliferating cells (cyan) expand the tissue, generating a mechanical pressure at the tissue center that drives the formation of the main tooth signaling center or organizer, the enamel knot. Credit Neha Pincha Shroff and Pengfei Xu Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.