Morphogen Gradient in a Leaf Primordium (image) National Institutes of Natural Sciences Share Print E-Mail Caption AN3 expression is visualized by using green fluorescent protein, GFP. Long-range gradient of AN3 can be seen from base (left) to tip (right), which was achieved by a simple diffusion-based model in the growing leaf. Credit NIBB Usage Restrictions None Share Print E-Mail 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.