Endochondral bone formation in embryonic mouse pre-metatarsals.
Long term exposure to a reduced gravitational environment has a deleterious effect on bone.  The developmental events which occur prior to initial bone deposition will provide insight into the regulation of mature bone physiology.  We have characterized a system in which the events preceding bone formation take place in an isolated in vitro organ culture environment.  We show that cultured pre-metatarsal tissue parallels development of pre-metatarsal tissue in the embryo.  Both undergo mesenchyme differentiation and morphogenesis to form a cartilage rod, which resembles the future bone, followed by terminal chondrocyte differentiation in a definite morphogenetic pattern.  These sequential steps occur prior to osteoblast maturation and bone matrix deposition in the developing organism.  Alkaline phosphatase (ALP) activity is a distinctive enzymatic marker for mineralizing tissues.  We have measured this activity throughout pre-metatarsal development and show (a) where in the tissue it is predominantly found, and (b) that this is indeed the mineralizing isoform of the enzyme.
Klement
B J
BJ
Division of Biology, Kansas State University, Manhattan 66506-4901, USA.
Spooner
B S
BS
D000469:Alkaline Phosphatase / Q000378:metabolism*; D000818:Animals; D001846:Bone Development / Q000502:physiology*; D002113:Calcification, Physiologic / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D003094:Collagen / Q000096:biosynthesis; D005109:Extracellular Matrix / Q000502:physiology; D005260:Female; D008648:Mesoderm / Q000166:cytology / Q000502:physiology; D008682:Metatarsal Bones / Q000033:anatomy & histology / Q000196:embryology* / Q000201:enzymology; D051379:Mice; D009924:Organ Culture Techniques; D014893:Weightlessness / Q000009:adverse effects
D003094:Collagen; D000469:Alkaline Phosphatase