Gruol D, Rawson J R, Haselkorn R
Biochim Biophys Acta. 1975 Nov 18;414(1):20-9. doi: 10.1016/0005-2787(75)90122-7.
Centrifugation of DNA from Euglena gracilis in Hg2+-CS2SO4 equilibrium gradients allows the chloroplast DNA to be separated clearly from the nuclear DNA. Cytoplasmic ribosomal RNA isolated from a heat-bleached strain hybridizes only to the nuclear DNA. The ribosomal RNA cistrons in the chloroplast DNA are not related to those in the nuclear DNA. A possible origin for the chloroplast genome is suggested by the observation that roughly one-fourth of the ribosomal RNA complementary sequences in chloroplast DNA anneal with RNA from the blue-green alga Anacystis nidulans.
在Hg2+-CS2SO4平衡梯度中对纤细裸藻的DNA进行离心，可使叶绿体DNA与核DNA清晰分离。从热漂白菌株中分离出的细胞质核糖体RNA仅与核DNA杂交。叶绿体DNA中的核糖体RNA顺反子与核DNA中的核糖体RNA顺反子无关。叶绿体DNA中大约四分之一的核糖体RNA互补序列与蓝藻集胞藻的RNA退火，这一观察结果提示了叶绿体基因组的一个可能起源。
