We investigated the expression of the small proteoglycans, decorin and @entity11188 , which are associated with osteoblast differentiation, and how this relates to the expression of @entity9356 and bone sialoprotein (BSP) early in the formation of bone in the @entity35 mandible by immunohistochemistry and in situ hybridization. The mandibles of @entity35 fetuses were collected on embryonic days 14 (E14) to E18. In situ hybridization showed that gene expression of decorin, @entity11188 , @entity9356 and BSP was not apparent in the developing mandible at E 14, but was expressed by newly differentiated osteoblasts at E15. The expression of these mRNAs increased linearly as the number of osteoblasts increased in specimens from E16 to E18. Immunohistochemistry showed that newly differentiated osteoblasts expressed @entity11188 moderately, decorin weakly, and @entity9356 and BSP faintly. The unmineralized bone matrices among the osteoblasts showed prominent staining for decorin, weak staining for @entity9356 and BSP, and very weak staining for @entity11188 . When the intercellular matrix was mineralized at E16, the mineralized bone matrix showed more prominent staining for @entity9356 and BSP, but lacked staining for decorin and @entity11188 . The same staining profile was observed during the subsequent phases of bone formation at E17 and E18. These results indicate that decorin, @entity11188 , @entity9356 and BSP are expressed at the gene and protein level by newly differentiated osteoblasts before the onset of matrix mineralization and that they could play a role in the earliest stages of bone formation. Negative proteoglycan staining in the mineralized bone matrix suggests that a loss of, or a sharp @entity393 concomitant with bone matrix mineralization.

Gene expression and immunohistochemical localization of decorin and XXXX in association with early bone formation in the developing mandible.

@entity11188 :: ('25181(Tax:10116)', 'Gene') :: ['biglycan'] @entity393 :: ('MESH:D034381', 'Disease') :: ['decrease in proteoglycans occurs'] @entity9356 :: ('81613(Tax:10116)', 'Gene') :: ['osteocalcin'] @entity35 :: ('10116', 'Species') :: ['rat']
@entity11188 :: (25181(Tax:10116),Gene) :: ['biglycan']
