GENETIC ANALYSIS OF CARCINOGENESIS IN RAINBOW TROUT

虹鳟鱼致癌的基因分析

• 批准号: 6239489
• 负责人: GARY H THORGAARD
• 金额: $ 24.47万
• 依托单位: OREGON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-05-01 至 1998-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6239489
• 关键词: aflatoxins; alternatives to animals in research; animal genetic material tag; benzanthracenes; chemical carcinogenesis; dosage; genetic manipulation; genetic mapping; genetic markers; loss of heterozygosity; neoplasm /cancer genetics; neoplastic process; nitroso compounds; nucleic acid probes; nucleic acid sequence; restriction fragment length polymorphism; trout /salmon; tumor suppressor genes

This project seeks to apply genetic manipulations possible in the trout system to examine genetic mechanisms of carcinogenesis. The study should provide basic insights into the carcinogenesis process using this non-mammalian vertebrate model. The first specific aim is to examine tumor incidence in diploid, triploid and clonal rainbow trout. In fish, unlike mammals, triploid individuals can be readily induced and are viable. In our studies to date, induced tumors were much more common in diploid than in triploid rainbow trout in three of four target organs tested. This might be due to the involvement of tumor suppressor genes in carcinogenesis in those tissues; triploids might be more tumor- resistant because it would be more difficult to inactivate or alter all three copies of a gene than just two. These interesting results need to be extended over a wider dose-response range for the three carcinogens studied to date (AFB1, DMBA, MNNG). Substantial differences in tumor susceptibility may also exist among clonal lines and analysis of these differences may provide insights into underlying genetic mechanism of carcinogenesis. The second specific aim is to test a large number of RFLP markers in tumor tissues from isogenic, hybrid trout for loss of heterozygosity. Screening for the loss of heterozygosity (LOH) with RFLP markers has been a primary tool for identifying candidate tumor suppressor genes in humans. The same approach should be useful in trout as well. RFLPs detectable using DNA fingerprint polymorphisms, trout cDNA probes and known human tumor suppressor gene probes, where feasible, will be screened for LOH. The third specific aim is to initiate development of a genetic map of DNA markers for a rainbow trout. It is important to document the proportion of the genome being scanned in our LOH studies. We will seek to map the DNA markers being used in our LOH studies by generating recombinant clonal lines from the two hybrid lines used in the LOH studies and by backcrossing the lines to one of their homozygous parents. This should also provide insights into the distribution of repetitive elements in the salmonid genome and chromosomal evolution in salmonids in light of their tetraploid ancestry.

该项目旨在将可能的基因操作应用于鳟鱼 系统检查致癌的遗传机制。 研究 应该利用这个提供对致癌过程的基本见解 非哺乳动物脊椎动物模型。 第一个具体目标是检查 二倍体、三倍体和克隆虹鳟鱼的肿瘤发病率。 在鱼中， 与哺乳动物不同，三倍体个体很容易被诱导并且 可行的。 在我们迄今为止的研究中，诱发肿瘤在以下人群中更为常见： 四个目标器官中的三个比三倍体虹鳟鱼的二倍体 已测试。 这可能是由于抑癌基因的参与所致 这些组织的致癌作用；三倍体可能更具肿瘤性 抗性，因为更难以灭活或改变所有 基因的三个拷贝而不是两个。 这些有趣的结果需要 三种致癌物的剂量反应范围扩大 迄今为止的研究（AFB1、DMBA、MNNG）。 肿瘤的显着差异 克隆系之间也可能存在易感性，并对这些克隆系进行分析 差异可能有助于深入了解潜在的遗传机制 致癌作用。 第二个具体目标是测试大量 RFLP 标记 来自同基因杂交鳟鱼的肿瘤组织，用于杂合性丧失。 使用 RFLP 标记筛选杂合性丢失 (LOH) 是鉴定候选肿瘤抑制基因的主要工具 人类。 同样的方法也适用于鳟鱼。 RFLP 可使用 DNA 指纹多态性、鳟鱼 cDNA 探针和 已知的人类肿瘤抑制基因探针，在可行的情况下，将 筛查 LOH。 第三个具体目标是启动遗传图谱的开发 虹鳟鱼的 DNA 标记。 记录下来很重要 我们的 LOH 研究中被扫描的基因组的比例。 我们将寻求 通过生成来绘制 LOH 研究中使用的 DNA 标记 LOH 中使用的两个杂交系的重组克隆系 研究并将这些品系与其纯合子之一回交 父母。 这也应该提供对分布的见解 鲑鱼基因组中的重复元件和染色体进化 鉴于鲑鱼的四倍体祖先。