Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Neurosurgery, Chang Gung Memorial Hospital at Linlou, Taoyuan, Taiwan; Research Center for Emerging Viral Infections, Chang Gung Memorial Hospital at Linlou, Taoyuan, Taiwan.
Biomed J. 2018 Oct;41(5):333-336. doi: 10.1016/j.bj.2018.07.003. Epub 2018 Nov 6.
Nucleolus is viewed as a plurifunctional center in the cell, tightly linked to ribosome biosynthesis. As a non-membranous structure, how the size of nucleolus is determined is a long outstanding question, and the possibility of "direct size scaling to the nucleus" was raised by genetic studies in fission yeast. Here, we used the model organism Caenorhabditis elegans to test this hypothesis in multi-cellular organisms. We depleted ani-2, ima-3, or C27D9.1 by RNAi feeding, which altered embryo sizes to different extents in ncl-1 mutant worms. DIC imaging provided evidence that in size-altering embryo nucleolar size decreases in small cells and increases in large cells. Furthermore, analyses of nucleolar size in four blastomeres (ABa, ABp, EMS, and P2) within the same embryo of ncl-1 mutants consistently demonstrated the correspondence between cell and nucleolar sizes - the small cells (EMS and P2) have smaller nucleoli in comparison to the large cells (ABa).
核仁被视为细胞中的多功能中心，与核糖体生物合成紧密相关。作为一种非膜结构，核仁的大小如何确定是一个长期存在的问题，有遗传研究在裂殖酵母中提出了“直接按比例缩放细胞核”的可能性。在这里，我们使用模式生物秀丽隐杆线虫在多细胞生物中测试了这一假设。我们通过 RNAi 喂养耗尽 ani-2、ima-3 或 C27D9.1，这导致 ncl-1 突变体蠕虫的胚胎大小发生不同程度的改变。DIC 成像提供了证据，表明在改变大小的胚胎中，核仁大小在小细胞中减小，在大细胞中增大。此外，在 ncl-1 突变体胚胎中的四个卵裂球（ABa、ABp、EMS 和 P2）中对核仁大小的分析一致表明细胞和核仁大小之间存在对应关系-小细胞（EMS 和 P2）的核仁比大细胞（ABa）小。
