Mutation & recombination in mice exposed to toxic metals

描述（摘自应用程序） 该项目的目的是更好地了解遗传毒性效应的 铬和砷在哺乳动物中，当这些金属被引入， 单独或与苯并[a]芘组合。研究设计采用了电池 新的小鼠品系，旨在检测移码和重组事件。 一组这样的小鼠使用人PLAP（胎盘碱性磷酸酶）基因。 通过插入7个G：C碱基对使PLAP基因失活。的 移码PLAP转基因在所有小鼠组织中普遍转录。 因此，当PLAP转基因中的移码突变回复时， 产生活性PLAP酶并沉积在细胞表面，其中 通过组织化学染色检测。这种方法提供了信息 突变细胞在不同组织中的位置使用PLAP的小鼠 表达以检测同向重复序列之间的缺失重组（PLAP-del mice）正在建设中。当PLAP-缺失小鼠正在开发时， 将在小鼠中研究暴露于金属后的间质缺失 一种叫粉眼不稳定的病毒这些老鼠被用来证明， 砷酸钠可诱导小鼠体内重组。然而，粉红色的眼睛不稳定 小鼠只能检测到胚胎前黑素细胞中的重组。相比之下， PLAP-缺失系统报道了所有组织中的重组。我们还将研究 有丝分裂的重组。这些 小鼠对于APRT基因是杂合的。淋巴细胞来源于 在aprt和 8号染色体上的着丝粒可以被选择，因为这样的细胞缺乏APRT 在2，6-二氨基嘌呤中起作用并存活。我们建议测试以下内容 假设：1）铬和砷诱导移码突变， 小鼠不同组织细胞中的同源重组。2)结合 这些金属中的一种或另一种与苯并[a]芘具有协同效应， 突变

DESCRIPTION (Taken from application) The goal of this project is to better understand the genotoxic effects of chromium and arsenic in mammals, when these metals are introduced either alone, or combined with benzo[a]pyrene. The research design employs a battery of novel mouse strains designed to detect frameshift and recombination events. One set of such mice uses a human PLAP (Placental Alkaline Phosphatase) gene. The PLAP gene was rendered inactive by insertion of 7 G:C basepairs. The frameshifted PLAP transgene is transcribed ubiquitously in all mouse tissues. Consequently, when the frameshift mutation in the PLAP transgene reverts, active PLAP enzyme is produced and deposited on the surface of the cell, where it is detected by a histochemical stain. This approach provides information about where mutant cells arise in different tissues. Mice that use PLAP expression to detect deletional recombination between direct repeats (PLAP-del mice) are under construction. While the PLAP-del mice are being developed, interstitial deletion after exposure to metals will be studied in a mouse strain called pink-eyed unstable. These mice have been used to show that sodium arsenate can induce recombination in mice. However, pink-eyed unstable mice can detect recombination in embryonic premelanocytes only. By contrast, the PLAP-del system reports recombination in all tissues. We will also study mitotic recombination by using another mouse strain we have developed. These mice are heterozygous for the aprt gene. Lymphocytes derived from cells that have undergone mitotic recombination at any point between aprt and the centromere on chromosome 8 can be selected because such cells lack APRT function and survive in 2, 6 diaminopurine. We propose to test the following hypotheses: 1) Chromium and arsenic induce frameshift mutations and homologous recombination in the cells of diverse tissues of mice. 2) Combining one or another of these metals with benzo[a]pyrene has a synergistic effect on mutation.