Regulation of Transgene Expression

工作总结：本工作的范围是 阐明引起诱导的 在Tg.AC小鼠中v-Ha- ras转基因的表达。我们的方法 在这项工作中，成功地实现了三个目标。第一 目的是获得一个分子机制的理解的作用 加塔-3（一种40 kd的锌指转录因子，已知其结合于 转基因启动子）在正常皮肤和肿瘤中起作用 发展表达构建体和转基因小鼠在 已经开发了它们的加塔-3的表达模式， 正在研究中。此外，加塔促进lacZ转基因小鼠 在詹姆斯·道格拉斯·恩格尔的实验室里， 西北大学已经被收购，应该提供宝贵的 加塔-3在肿瘤发生和皮肤中作用信息 发展实验室的第二个主要目标是 转录因子的鉴定及其各自的顺式结合 活性转录的v-HA-ras启动子上的位点。dna酶I 足迹实验比较的占用区域的 活性转录的转基因与非活性基因的比较正在进行中。 鉴于大多数因素及其位置已在 珠蛋白系统（转基因具有zetaglobin启动子）a 比较应确定其他因素必不可少的诱导 反应和肿瘤发生所需。最后一种方法是 获得转基因周围的染色体区域。给定 只有五分之一的转基因创始人 肿瘤发生表型，整合位点可能是 重要.在一项合作努力中，我们正在使用TAR 这项技术是在迈克·雷斯尼克的实验室里发明的， Tg.AC的转基因侧翼的染色体区域。鉴定 Tg.AC的致瘤反应所需的区域将是必不可少的。 除此之外，我们还将继续与其他 科学家在我们的实验室利用Tg的可靠性。 致瘤反应的时间和位置， 确定遗传和表观遗传的变化， 肿瘤发生过程

Summary of Work: The scope of this work is to elucidate the molecular mechanisms that give rise to the induced expression of the v-Ha- ras transgene in Tg.AC mice. Our approach in this work is to successufully accomplish three goals. The first goal is to obtain a molecular mechanistic understanding of the role GATA-3 (a 40 kd zinc finger transcription factor known to bind to the transgene promoter) plays in both normal skin and tumor development. Expression constructs and transgenic mice altered in their expression pattern for gata-3 have been developed and are under study. Also, GATA promoted lacZ transgenic mice developmented in the labotratory of James Douglas Engel at Northwestern have been procured and should provide valuable information about GATA-3 role in both tumorigenesis and skin development. The second major goal of the laboratory is the identification of transcription factors and their respective cis binding sites on the actively transcribed v- HA-ras promoter. DNase I footprint experiments comparing the occupied regions of the actively transcribed transgene versus the inactive gene are ongoing. Given that most factors and their sites have been identified in the globin system (the transgene has a zetaglobin promoter) a comparison should identify other factors essential to the induced response and reguired for tumorigensis. The last approach is to obtain the chromosomal regions surronding the transgene. Given that only one of five of the transgenic founders displayed a skin tumorigenic phenotype it is likely that the site of integration is important. In a collaborative effort we are using the TAR technique, developed in Mike Resnick's laboratory to clone the chromsomal regions that flank Tg.AC's transgene. Identification of regions required for Tg.AC's tumorigenic response will be essential. In addition to this work we will continue to work with other scientist in our laboratory to exploit the reliability of Tg.ACs tumorigenic response both with regard to the time and location to identify genetic and epigenetic changes important for the tumorigenic process.