通过微柱凝胶过滤法测定嗜菌摇蚊多线染色体的DNA和RNA含量。

DNA and RNA content of Chironomus thummi polytene chromosomes determined by micro column gel filtration.

作者信息

Serfling E, Majorov V I, Mikichur N I, Popova T G, Sandakchiev L S

出版信息

Cell Differ. 1975 Mar;3(6):361-70. doi: 10.1016/0045-6039(75)90004-4.

Abstract

A new microtechnique was used to determine the nucleic acid content of Chironomus polytene chromosomes. The method based on UV-microspectrophotometric measurement of alkali digested chromosome samples before and after gel filtration through Sephadex microcolumns permits the simultaneous estimation of DNA as well as RNA amount of single chromosomes and nucleoli. The DNA and RNA content of C. thummi salivary gland chromosomes I-III carrying a large number of puffs (but no nucleoli or Balbiani rings) corresponds roughly to their relative lengths. Chromosomes of the most frequent polyteny level (class B; probably 8192 C) contain 418 (Chromosome I), 372 (II), and 307 times 10-12 g DNA (III) and 116, 120 and 69 times 10-12 g RNA, respectively. The 4th chromosome, which carries the nucleolus and two Balbiani rings, contains about 150 times 10-12 g DNA and 328 times 10-12 g RNA. As the result of one of the last replication steps both DNA and RNA content of chromosomes I-III becomes duplicated whereas nucleolar RNA content is increased to a smaller extent.

摘要

一种新的显微技术被用于测定摇蚊多线染色体的核酸含量。该方法基于对通过Sephadex微柱凝胶过滤前后的碱消化染色体样品进行紫外显微分光光度测量，可同时估算单条染色体和核仁的DNA以及RNA含量。携带大量胀泡（但无核仁或巴尔比亚尼环）的嗜尸摇蚊唾液腺I - III号染色体的DNA和RNA含量大致与其相对长度相符。最常见的多线化水平（B类；可能为8192C）的染色体含有418（I号染色体）、372（II号染色体）和307×10⁻¹²克DNA（III号染色体）以及116、120和69×10⁻¹²克RNA。携带核仁及两个巴尔比亚尼环的4号染色体含有约150×10⁻¹²克DNA和328×10⁻¹²克RNA。作为最后复制步骤之一的结果，I - III号染色体的DNA和RNA含量均加倍，而核仁RNA含量的增加幅度较小。