Lynn Kee, Graduate Student (Verhey Laboratory), Department of Cell and Developmental Biology, University of Michigan Medical School
This is an image of the intricate junction between the vertebrae of the backbone, tail and hindlimb of a veiled chameleon lizard embryo (Chamaeleo calyptratus). In this preparation, bone is stained yellow and cartilage is stained blue. These bones are forming by a process called endochondral ossification, in which a cartilage template is formed first and then is later partially replaced by bone. In regions of contact between the joints, cartilage can act as a smooth surface to allow easy movement. The chameleon has to move its limbs and tail independently; their prehensile tail acts as a fifth limb and helps the lizard with climbing trees. This image was prepared at the 2011 Woods Hole Embryology Course.