2016遗传学课件(第3章遗传的分子基础)白.pdf

3 遗传的分子基础 3.1 核酸是遗传物质 1868年J.T.Miescher 发现核素 （nuclein ） 遗传物质必须具备哪些特点？ 1）在体细胞中含量稳定； 2) 在生殖细胞中含量减半； 3) 能携带遗传信息； 4) 能精确地自我复制； 5) 能发生变异； 1869年，F.Miescher 从脓细胞中提取到 一种富含磷元素的 酸性化合物。 The whole family of Friedrich Miescher Fig. 2. Photograph of Felix Hoppe-Seylers laboratory around 1879. Prior to becoming the chemical laboratory of Tübingen University in 1823, this room was Tübingen castles laundry. Here, Hoppe-Seyler had made ground-breaking discoveries regarding the properties of hemoglobin. This achievement was a significant step for later investigations into the properties and functions of this and other proteins. Photography by Paul Sinner, Tübingen. Fig. 4. The laboratory in the former kitchen of the castle in Tübingen as it was in 1879. It was in this room that Miescher had discovered DNA 10 years earlier. The equipment and fixtures available to Miescher at the time would have been very similar, with a large distillation apparatus in the far corner of the room to produce distilled water and several smaller utensils, such as glass alembics and a glass distillation column on the side board. Photography by Paul Sinner, Tübingen. Fig. 5. Glass vial containing nuclein isolated from salmon 大麻哈鱼sperm by Friedrich Miescher while working at the University of Basel. The faded label reads “Nuclein aus Lachssperma, F. Miescher” (Nuclein from salmon sperm, F. Miescher). Possession of the Interfakultäres Institut für Biochemie (Interfacultary Institute for Biochemistry), University of Tübingen, Germany; photography by Alfons Renz, University of Tübingen, Germany.  1885—1900年间， Kossel 、Johnew 、 Levene证实核酸由 不同的碱基组成。 其最简单的单体结