Lynn Kee, Graduate Student, Cell and Developmental Biology
This image is of the base of a developing mouse embryo's skull as it is progressing through the process called endochondral ossification. In this process, cartilage is formed first and acts as a template for the later formation of bony tissue (ossification). The base of the skull as well as the long bones of the body form by endochondral ossification. Flat bones of the top of the skull form by a different process called intramembranous ossification, that do not require a cartilage template. In this image, regions in blue and green are composed of cartilage while red is the growing bony tissue. This image was prepared at the 2011 Woods Hole Embryology Course.