Zienkiewicz K, Bednarska E
Department of Cell Biology, Institute of General and Molecular Biology, Nicolaus Copernicus University, 87-100 Toruń, Poland.
Int J Cell Biol. 2009;2009:209303. doi: 10.1155/2009/209303. Epub 2009 Jun 25.
The aim of the present work was the characterization of nuclear bodies in the microspore and developing pollen cells of Hyacinthus orientalis L.. The combination of Ag-NOR, immunofluorescence and immunogold techniques was used in this study. The obtained results showed the presence of highly agyrophylic extranucleolar bodies in microspore and developing pollen cells, which were finally identified as Cajal bodies. In all cases, a strong accumulation of snRNP-indicating molecules including TMG cap, Sm proteins and U2 snRNA, was observed in the examined nuclear bodies. In contrast to their number the size of the identified structures did not change significantly during pollen development. In the microspore and the vegetative cell of pollen grains CBs were more numerous than in the generative cell. At later stages of pollen development, a drastic decrease in CB number was observed and, just before anthesis, a complete lack of these structures was indicated in both pollen nuclei. On the basis of these results, as well as our previous studies, we postulate a strong relationship between Cajal body numbers and the levels of RNA synthesis and splicing machinery elements in microspore and developing pollen cells.
本研究的目的是对风信子小孢子和发育中的花粉细胞中的核体进行表征。本研究采用了银染核仁组织区（Ag-NOR）、免疫荧光和免疫金技术相结合的方法。所得结果表明，在小孢子和发育中的花粉细胞中存在高度嗜银的核仁外体，最终鉴定为卡哈尔体（Cajal bodies）。在所有情况下，在所检测的核体中均观察到包括三甲基鸟苷（TMG）帽、Sm蛋白和U2小核RNA（snRNA）在内的snRNP指示分子的强烈积累。与它们的数量相反，所鉴定结构的大小在花粉发育过程中没有显著变化。在小孢子和花粉粒的营养细胞中，卡哈尔体比生殖细胞中的更多。在花粉发育的后期，观察到卡哈尔体数量急剧减少，并且在开花前不久，两个花粉核中均显示完全缺乏这些结构。基于这些结果以及我们之前的研究，我们推测卡哈尔体数量与小孢子和发育中的花粉细胞中RNA合成及剪接机制元件水平之间存在密切关系。
