Xing Y, Johnson C V, Dobner P R, Lawrence J B
Department of Cell Biology, University of Massachusetts Medical Center, Worcester 01655.
Science. 1993 Feb 26;259(5099):1326-30. doi: 10.1126/science.8446901.
Visualization of fibronectin and neurotensin messenger RNAs within mammalian interphase nuclei was achieved by fluorescence hybridization with genomic, complementary DNA, and intron-specific probes. Unspliced transcripts accumulated in one or two sites per nucleus. Fibronectin RNA frequently accumulated in elongated tracks that overlapped and extended well beyond the site of transcription. Splicing appears to occur directly within this RNA track, as evidenced by an unambiguous spatial separation of intron-containing and spliced transcripts. Excised introns for neurotensin RNA appear free to diffuse. The transcription and processing site of the fibronectin gene localized to the nuclear interior and was associated with larger transcript domains in over 88 percent of the cells. These results support a view of nuclear function closely integrated with structure.
通过与基因组、互补DNA和内含子特异性探针进行荧光杂交，实现了在哺乳动物间期核内对纤连蛋白和神经降压素信使RNA的可视化。未剪接的转录本在每个细胞核的一两个位点积累。纤连蛋白RNA经常在重叠且延伸至转录位点之外的细长轨迹中积累。内含子RNA和剪接转录本在空间上的明确分离证明，剪接似乎直接在这个RNA轨迹内发生。切除的神经降压素RNA内含子似乎可以自由扩散。在超过88%的细胞中，纤连蛋白基因的转录和加工位点定位于核内部，并与更大的转录本结构域相关。这些结果支持了一种核功能与结构紧密整合的观点。
