Modeling the 3-D RNA distribution in the Balbiani ring granule.
Modeling the 3-D RNA distribution in the Balbiani ring granule.
复制标题
模拟 Balbiani 环颗粒中的 3-D RNA 分布。
DOI：
10.1007/bf00417877
复制
发表时间：
1994
期刊：
影响因子：
1.6
通讯作者：
Bazett-Jones,DP
中科院分区：
文献类型：
--
作者：
Olins,AL;Olins,DE;Olman,V;Levy,HA;Bazett-Jones,DP
成熟的Balbiani环（BR）颗粒原位染色的核酸特异性染料，锇胺-B，记录电子光谱成像和重建的电子显微镜断层扫描检查的三维（3-D）分布的BR异质核RNA（hnRNA）。BR 2颗粒含有ca. 37 kb的mRNA。选择重建的BR颗粒以强调在切片唾液腺中观察到的一种普遍构象，即“针轮”构象。各种图像处理和体绘制操作被施加到重建的BR颗粒的集合。本研究的一些结论如下：（1）RNA在整个颗粒中的分布是不均匀的;（2）RNA被浓缩成每个颗粒约10个颗粒，它们似乎都具有大致相同的RNA染色密度;（3）在各种BR颗粒内颗粒的位置和大小存在异质性。这些数据认为，折叠的珠状带，连接的颗粒状的BR mRNA的缩合物组成，具有相当大的3-D的灵活性，即使在包装状态。还提出了这种beadedrificial模型和先前折叠hnRNP纤维模型的比较。
Mature Balbiani Ring (BR) granules in situ were stained with the nucleic acid specific stain, osmium ammine-B, recorded by electron spectroscopic imaging and reconstructed by electron microscope tomography to examine the three-dimensional (3-D) distribution of BR heterogeneous nuclear RNA (hnRNA). The BR2 granules contain ca. 37 kb of mRNA. Reconstructed BR granules were selected to emphasize one of the prevalent conformations seen in the sectioned salivary glands, theen faceor “pin-wheel” conformation. A variety of image processing and volume-rendering operations were applied to the set of reconstructed BR granules. Some of the conclusions of this study are the following: (1) RNA distribution is not uniform throughout the granule; (2) RNA is condensed into about ten particles per granule, which all appear to possess approximately the same RNA stain density; (3) heterogeneity exists in the positions and sizes of particles within the various BR granules. These data argue for the folding of a beaded ribbon, consisting of connected particulate condensations of BR mRNA, possessing considerable 3-D flexibility, even in the packaged state. A comparison of this beadedribbon model and a prior folded hnRNP fiber model is also presented.