PDF(Pubmed)
Abstract：
Nuclear speckles are compartments enriched in splicing factors present in the nucleoplasm of eucaryote cells. Speckles have been studied in mammalian culture and tissue cells, as well as in some non-mammalian vertebrate cells and invertebrate oocytes. In mammals, their morphology is linked to the transcriptional and splicing activities of the cell through a recruitment mechanism. In rats, speckle morphology depends on the hormonal cycle. In the present work, we explore whether a similar situation is also present in non-mammalian cells during the reproductive cycle. We studied the speckled pattern in several tissues of a viviparous reptile, the lizard Sceloporus torquatus, during two different stages of reproduction. We used immunofluorescence staining against splicing factors in hepatocytes and oviduct epithelium cells and fluorescence and confocal microscopy, as well as ultrastructural immunolocalization and EDTA contrast in Transmission Electron Microscopy. The distribution of splicing factors in the nucleoplasm of oviductal cells and hepatocytes coincides with the nuclear-speckled pattern described in mammals. Ultrastructurally, those cell types display Interchromatin Granule Clusters and Perichromatin Fibers. In addition, the morphology of speckles varies in oviduct cells at the two stages of the reproductive cycle analyzed, paralleling the phenomenon observed in the rat. The results show that the morphology of speckles in reptile cells depends upon the reproductive stage as it occurs in mammals.
摘要：
核斑点是富含存在于真核细胞核质中的剪接因子的区室。斑点已经在哺乳动物培养和组织细胞中进行了研究，以及一些非哺乳动物脊椎动物细胞和无脊椎动物卵母细胞。在哺乳动物中,它们的形态通过募集机制与细胞的转录和剪接活动有关。在老鼠身上,斑点形态取决于荷尔蒙周期。在目前的工作中,我们探讨在生殖周期的非哺乳动物细胞中是否也存在类似的情况。我们研究了胎生爬行动物的几个组织中的斑点图案，蜥蜴Sceloporustorquatus,在两个不同的繁殖阶段。我们使用免疫荧光染色对肝细胞和输卵管上皮细胞的剪接因子和荧光和共聚焦显微镜，以及透射电子显微镜中的超微结构免疫定位和EDTA对比。剪接因子在输卵管细胞和肝细胞核质中的分布与哺乳动物中描述的核斑点模式一致。超微结构，这些细胞类型显示染色质间颗粒簇和环磷素纤维。此外,在生殖周期的两个阶段，输卵管细胞中斑点的形态有所不同，与在大鼠中观察到的现象平行。结果表明，爬行动物细胞中斑点的形态取决于哺乳动物的生殖阶段。
