多头绒泡菌的变形虫状和原质团状形态中的核糖体RNA基因。

Ribosomal RNA genes in the amoebal and plasmodial forms of the slime mould Physarum polycephalum.

作者信息

Hall L, Turnock G, Cox B J

出版信息

Eur J Biochem. 1975 Feb 21;51(2):459-65. doi: 10.1111/j.1432-1033.1975.tb03945.x.

DOI:10.1111/j.1432-1033.1975.tb03945.x

Abstract

The degree of homology between ribosomal RNA isolated from microplasmodia and amoebae of the slime mould Physarum polycephalum has been determined by competive hybridisation of the RNA from the two sources to homologous DNA in solution. The extent of competition was measured both by hybridisation to saturation and by following the kinetics of hybrid formation. In each case competition was found to be 100%, indicating that the ribosomal RNAs from the two, quite different vegetative forms of the organism exhibit a high degree of homology and are probably transcribed from the same genes. 2. The relationship between the amount of nuclear DNA that codes for ribosomal RNA (rDNA) and ploidy has been investigated in three strains of P. polycephalum which exhibit a 1:2:5 variation in the amount of DNA per nucleus. Ribosomal RNA saturation values were determined by hybridisation to DNA isolated from prophase nuclei of plasmodia. The proportion of rDNA was found to be constant at 0.16--0.18% of the total genome in the three strains.

摘要

通过将来自这两个来源的RNA与溶液中的同源DNA进行竞争性杂交，测定了从微疟原虫和多头绒泡菌的变形虫中分离出的核糖体RNA之间的同源程度。竞争程度通过杂交至饱和以及跟踪杂交形成动力学来测量。在每种情况下，都发现竞争率为100%，这表明来自该生物体两种截然不同营养形式的核糖体RNA表现出高度同源性，并且可能是从相同基因转录而来的。2. 在多头绒泡菌的三个菌株中研究了编码核糖体RNA（rDNA）的核DNA量与倍性之间的关系，这三个菌株每个细胞核中的DNA量呈现1:2:5的变化。核糖体RNA饱和值通过与从疟原虫前期细胞核中分离的DNA杂交来确定。在这三个菌株中，发现rDNA的比例恒定在总基因组的0.16 - 0.18%。