OBJECTIVETo investigate the expression patterns of osterix in the early stage of cranio-maxillofacial developmental in zebrafish and to prepare for a further research of osterix gene in bone and tooth development.

METHODSThe osterix templates were amplified by PCR to generate DIG labeled antisense and sense probes. Whole mount in situ hybridization was used to analyze the expression patterns of osterix in the early stage cranio-maxillofacial development of zebrafish. The expression patterns of osterix gene in mineralization progresses of cranial and maxillofacial bones were compared. The osterix gene expression in tooth development and mineralization was highlighted by alizarin red staining.

RESULTSSpecific DIG labeled probes of osterixwere synthesized successfully. The whole mount in situ hybridization showed that the osterix expression was in the intramembranous ossification at 3 days post fertilization(dpf) and 4 dpf. The specific osterix expression in tooth at 5 dpf and 6 dpf were also observed. The sense probe served as a negative control. Osterix expressed in the unmineralized early bone matrix, the tooth matrix of the primary tooth(3V(1), 5V(1)) and the first replacement tooth(4V(2)).

CONCLUSIONSOur findings showed that osterix might play roles in the process of the early mineralized bone matrix changing into the late mature mineralized bone matrix and the process of development and mineralization of tooth crown matrix.