IN VIVO MUTAGENESIS STUDIES USING TRANSGENIC MICE

而特定的细胞突变机制通常是最 方便地在体外研究，组织反应的差异，在 化学沉积或在不同类型的细胞对 诱变剂/致癌物暴露只能在体内定义。我们的目标是 利用分子生物学技术设计出 利用转基因啮齿动物模型进行定量研究的策略和模型 体内突变的测定。我们继续定义 有助于分析基因突变的实验和统计方法 VIVO还在继续。化验可变性的领域已经被仔细地 用于数据分析的已定义和统计方法 发展起来的。此外，我们正在使用大型蓝色系统来评估 细胞增殖对突变产率的影响 是否存在DNA损伤。黄曲霉毒素的体内致突变活性 致癌物/非致癌物对，2，4-或2，6-二氨基甲苯与 这些异构体的致癌潜力表明细胞 2，4-DAT诱导的增殖似乎是必要的先决条件 在大蓝鼠身上产生突变反应。最后，我们有 进一步研究了细胞增殖的影响 苯并[a]芘治疗后小鼠肝部分切除 (B[a]P)。在牺牲时，MF的增加显著不同于 将处理后的小鼠与对照组进行比较。然而，牺牲的MF 与肝切除时并无显著差异， 这表明在复制细胞中MF没有发生任何程度的改变 如果在肝脏完全再生之前评估MF。 这些数据强调了在评估 细胞增殖对体内突变固定的影响。

While specific cellular mutational mechanistic pathways are often most conveniently studied in vitro, differences in tissue response, in chemical deposition or in the response of different cell types to mutagen/carcinogen exposure can only be defined in vivo. Our goal is to take advantage of the techniques of molecular biology to devise strategies and models using transgenic rodent models for the quantitative determination of in vivo mutations. We continue to define the experimental and statistical methods useful for analyzing mutations in vivo have continued. Areas of assay variability have been carefully defined and statistical approaches for the analysis of data have been developed. In addition, we are using the Big Blue system to assess the effects of cellular proliferation on the yield of mutations either in the presence or absence of DNA damage. The in vivo mutagenic activity of the carcinogen/noncarcinogen pair, 2,4- or 2,6-diaminotoluene correlates with the carcinogenic potential of these isomers suggesting that cellular proliferation induced by 2,4-DAT appears to be a necessary prerequisite for generating a mutational response in Big Blue mice. Finally, we have further studied the effects of cellular proliferation by subjecting the mice to partial hepatectomy following treatment with benzo[a]pyrene (B[a]P). The increase in MF at sacrifice was significantly different in the treated mice compared to the controls. However, the MF at sacrifice was not significantly different from that at the time of hepatectomy, suggesting that MF is not altered to any extent in the replicating cells if the MF is evaluated before the liver has completely regenerated. These data underscore the importance of timing when evaluating the effects of cell proliferation on mutation fixation in vivo.