Parfenov V N, Davis D S, Pochukalina G N, Kostyuchek D, Murti K G
Institute of Cytology, Russian Academy of Science, St. Petersburg, Russia.
J Cell Biochem. 1998 Apr 1;69(1):72-80. doi: 10.1002/(sici)1097-4644(19980401)69:1<72::aid-jcb8>3.0.co;2-s.
The distribution of two splicing components (snRNP and SC-35) and coilin were studied by immunogold/electron microscopy in human oocytes from antral follicles at different levels of transcriptional activity (i.e., active, intermediate, and inactive). The results showed a decrease of snRNPs and SC-35 in the karyoplasm as the oocytes progress from a transcriptionally active to the inactive state. The main areas of accumulation of both these splicing components in all stages of oocytes appeared to be the interchromatin granule clusters (IGCs). Within the IGCs, the two splicing components seemed to be spatially segregated, with the snRNPs predominantly bound to the fibrillar region, whereas the SC-35 factors are being enriched in the granular zone. The p80 coilin was found only in the nucleolus-like body (NLB), which is present in all three stages of oocytes; no coiled bodies were evident. These data are consistent with the notion that splicing occurs in the karyoplasm and that the splicing components are mobilized from a storage site (IGCs) to the site of action.
通过免疫金/电子显微镜技术，研究了两种剪接成分（snRNP和SC-35）以及卷曲螺旋蛋白在不同转录活性水平（即活跃、中间和非活跃）的有腔卵泡人卵母细胞中的分布情况。结果显示，随着卵母细胞从转录活跃状态转变为非活跃状态，核质中的snRNP和SC-35减少。在卵母细胞的所有阶段，这两种剪接成分的主要积累区域似乎都是染色质间颗粒簇（IGC）。在IGC内，这两种剪接成分似乎在空间上是分离的，snRNP主要与纤维状区域结合，而SC-35因子则在颗粒区富集。p80卷曲螺旋蛋白仅在核仁样体（NLB）中发现，NLB存在于卵母细胞的所有三个阶段；未发现明显的卷曲小体。这些数据与剪接发生在核质中且剪接成分从储存位点（IGC）转移到作用位点的观点一致。
