A Novel Mechanism for Introducing Human Genome Research in Freshman Biology Classes

在新生生物学课程中引入人类基因组研究的新机制

• 批准号: 9455075
• 负责人: Mark Bloom
• 金额: $ 21.85万
• 依托单位: Cold Spring Harbor Laboratory
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-05-01 至 1998-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9455075&HistoricalAwards=false
• 关键词: Novel; Mechanism; Introducing; Human; Genome

This experiment uses the powerful new technique of polymerase chain reaction (PCR) to demonstrate the variable nature of human DNA. Although the DNA from one person to another is more alike than different, certain areas of our genome exhibit a great deal of diversity. Such variable sequences are termed polymorphic (meaning many forms) and provide the basis for paternity and forensic testing of DNA. Many DNA polymorhisms are found within the estimated 90% of the genome that does not code for protein. A special class of these polymorphisms is called an Alu insertion. Alu elements are short DNA sequences that have amplified to about 500,00 copies, distributed throughout primate genomes. A few of these Alu insertions have occurred within the last million years and are not fixed in the human genome. Students obtain samples of their own DNA using a simple mouthwash procedure (bloodless and noninvasive). PCR is used to amplify across an intron of the tissue plasminogen activator gene that may contain an Alu insertion. If the Alu sequence is present, then a 400-bp PCR product will result, while a 100-bp product is produced when the Alu sequence is absent. Following amplification, student samples are loaded into an agarose gel, electrophoresed, stained, and photographed. Each student will see one or two bands in their gel lane, indicating whether they are homozygous for the Alu insertion, homozygous for the absence of the insertion, or heterozygous for the insertion.

这项实验使用了强大的聚合酶链式反应(PCR)这一新技术来证明人类DNA的可变性。尽管人与人之间的DNA相似多于不同，但我们基因组的某些区域表现出了极大的多样性。这种可变序列被称为多态(指多种形式)，并为DNA的亲子鉴定和法医鉴定提供了基础。据估计，在不编码蛋白质的基因组的90%内发现了许多DNA多态。这种多态的一种特殊类型被称为Alu插入。Alu元件是一种短DNA序列，已扩增到约500，00个拷贝，分布在灵长类动物基因组中。其中一些Alu插入发生在过去的100万年内，并没有固定在人类基因组中。学生使用简单的漱口水程序(不流血和非侵入性)获得他们自己的DNA样本。聚合酶链式反应被用来在组织纤溶酶原激活剂基因的内含子上扩增，该内含子可能包含Alu插入。如果存在Alu序列，则产生400bp的聚合酶链式反应产物，而当不存在Alu序列时，产生100bp的产物。扩增后，学生样本被装载到琼脂糖凝胶中，进行电泳、染色和拍照。每个学生都会在他们的凝胶中看到一条或两条带，表明它们是Alu插入的纯合子，没有插入的纯合子，还是插入的杂合子。