Haff L A, Bogorad L
Biochemistry. 1976 Sep 7;15(18):4110-5. doi: 10.1021/bi00663a030.
Hybridization experiments with chloroplast DNA and 125I-labeled RNA from maize seedlings suggest that chloroplasts and etioplasts contain detectable amounts of RNA that contains poly(adenylic aicd) (poly (A)) and was transcribed from chloroplast DNA. About 6% of the total poly(A)-containing RNA isolated from maize seedlings hybridized to chloroplast DNA. Poly(A)-containing RNA could also be isolated directly from purified chloroplasts that were treated with ribonucleases to reduce cytoplasmic contamination. At least 65% of this poly(A)-containing RNA hybridized to chloroplast DNA. Chloroplast poly(A) tracts average about 45 nucleotides in length, one-half the average size of poly(A) tracts from whole cells. The poly (A) tracts themselves are probably added to plastid RNAs following their transcription, because maize chloroplast DNA was found not to contain poly(dT).
用玉米幼苗的叶绿体DNA和125I标记的RNA进行的杂交实验表明，叶绿体和黄化质体含有可检测量的RNA，这些RNA含有聚腺苷酸（poly(A)），并且是由叶绿体DNA转录而来的。从玉米幼苗中分离出的总含poly(A) RNA中约6%与叶绿体DNA杂交。含poly(A) RNA也可以直接从用核糖核酸酶处理以减少细胞质污染的纯化叶绿体中分离出来。这种含poly(A) RNA中至少65%与叶绿体DNA杂交。叶绿体poly(A)序列平均长度约为45个核苷酸，是全细胞poly(A)序列平均大小的一半。poly(A)序列本身可能在转录后添加到质体RNA上，因为发现玉米叶绿体DNA不含有聚胸苷酸（poly(dT)）。
