中文摘要：

构建了含有骨钙素基因启动子、Cre重组酶基因和人生长激素基因polyA的转基因载体pOC-Cre,以显微注射的方法将4.6 kb的转基因片段OC-Cre导入小鼠受精卵。16只子代小鼠中经PCR和Southern杂交鉴定,有2只小鼠携带外源基因,整合率为12.5%。为了检测OC-Cre在转基因小鼠中表达的组织特异性,将转基因首建者小鼠与基因组上携带有LoxP位点的条件性Smad4基因敲除小鼠交配,PCR结果显示,仅在子代纯合型小鼠骨组织基因组中扩增出了Cre介导重组后的片段。将OC-Cre转基因小鼠与ROSA26报告小鼠交配,利用LacZ染色对双转基因阳性子代小鼠进行检测,结果显示Cre重组酶在成骨细胞中特异性表达并介导ROSA基因座LoxP位点间的重组。所有这些结果说明：所建立的OC-Cre转基因小鼠在成骨细胞中特异性表达Cre重组酶,并能在体内介导成骨细胞基因组上LoxP位点间的重组,是一种理想的研制成骨细胞特异性基因敲除小鼠的工具小鼠。

英文摘要：

An osteoblast-specific Cre transgenic construct （pOC-Cre） containing the osteocalcin promoter, Cre recombinase gene and polyA of human growth hormone gene was generated. The 4.6 kb DNA fragment of OC-Cre was introduced into fertilized zygotes by microinjection. 2 out of 16 offspring were identified as founders carrying the transgene by PCR and Southern blot analysis, and the integration efficiency is 12.5 %. To check the tissue distribution of the OC-Cre, the OC-Cre transgenic founder mice were bred with the mice carrying Smad4 conditional alleles. PCR results showed that the genomic DNA fragments after Cre mediated recombination could be only amplified from bone tissues of the transgenic mice. LacZ staining of OC-Cre; ROSA26 double transgenic mice revealed that Cre recombinase expressed in osteoblasts and mediated DNA recombination between LoxP sites at the ROSA26 locus. All these data indicated that the Cre recombinase was expressed in the osteoblasts of the OC-Cre transgenic mice and could mediate DNA recombination between LoxP sites. The OC-Cre transgenic mice we generated in this study could serve as a useful tool for generating osteoblast specific gene-knockout mice.