Mineralization is both a biological and physico-chemical process. The mechanisms involved in mineralization of skeletal organs are not well understood. The least understood mechanism is that in bone, especially woven compared to lamellar. There are several schools of thought regarding the initiation and regulation of this process. One mechanism utilizes matrix vesicles, organelles that initiate or nucleate mineral. Another is collagen mediated mineralization of bone. It is well accepted that osteoblasts are the bone cell type that initiate mineralization, however, the cell embedded in osteoid just ahead and within the mineralization front, the osteoid-osteocyte, may also initiate and regulate the mineralization process. The overall hypothesis to be tested is that osteoid-osteocytes in bone initiate and regulate mineralization through processes distinct from cartilage and other skeletal structures. To study this process in bone, we have proposed the following specific aims:​ 1) To characterize the mineralization process using a bone-like cell line, MLO-A5, 2) To determine the role of El 1 in the osteoblast to osteocyte transition, and 3) To determine the effect of Parathyroid Hormone (PTH) on mineralization. We propose that E11 is necessary for the formation of dendritic processes of osteoid-osteocytes. This mechanism is activated by mechanical strain, fluid flow shear stress.