An investigation of cellular dynamics during the development of intramembranous bones: the scleral ossicles.

摘要: The development of intramembranous bone is a dynamic and complex process requiring highly coordinated cellular activities. Although the literature describes detailed dynamics early mesoderm-derived endochondral bone, studies regarding neural crest-derived have failed to keep pace. We analyzed chick scleral ossicles from onset osteoid deposition mineralization at morphological, histological, ultrastructural levels. find that mesenchymal condensations which develop change their shape ellipsoidal trapezoidal concurrent with an increase in size. Furthermore, size ossicle dependent upon its time induction. Our histological analyses condensation growth reveal cell migration secretion as key processes determining size; these occur concomitantly both area thickness condensations. also describe formation zone overlap between conclude similar cranial suture formation. Finally, transmission electron microscopy demonstrates osteoblasts secrete collagen parallel long axis condensation. This study elucidates fundamental mechanisms level, furthering our knowledge this important among vertebrates.