Department of Biological Sciences and Institute of Molecular Biology and Genetics, College of Natural Sciences, Seoul National University, 599, Gwanak-Ro, Gwanak-Gu, Seoul 151-742, Korea.
Dev Biol. 2010 Sep 1;345(1):34-48. doi: 10.1016/j.ydbio.2010.06.004. Epub 2010 Jun 8.
Polo-like kinase 1 (Plk1) is central to cell division. Here, we report that Plk1 is critical for mitosis in the embryonic development of zebrafish. Using a combination of several cell biology tools, including single-cell live imaging applied to whole embryos, we show that Plk1 is essential for progression into mitosis during embryonic development. Plk1 morphant cells displayed mitotic infidelity, such as abnormal centrosomes, irregular spindle assembly, hypercondensed chromosomes, and a failure of chromosome arm separation. Consequently, depletion of Plk1 resulted in mitotic arrest and finally death by 6days post-fertilization. In comparison, Plk2 or Plk3 morphant embryos did not display any significant abnormalities. Treatment of embryos with the Plk1 inhibitor, BI 2536, caused a block in mitosis, which was more severe when used to treat plk1 morphants. Finally, using an assay to rescue the Plk1 morphant phenotype, we found that the kinase domain and PBD domains are both necessary for Plk1 function in zebrafish development. Our studies demonstrate that Plk1 is required for embryonic proliferation because its activity is crucial for mitotic integrity. Furthermore, our study suggests that zebrafish will be an efficient and economical in vivo system for the validation of anti-mitotic drugs.
丝氨酸/苏氨酸激酶 1（Plk1）是细胞分裂的核心。在这里，我们报告 Plk1 对斑马鱼胚胎发育中的有丝分裂至关重要。我们使用了几种细胞生物学工具的组合，包括应用于整个胚胎的单细胞实时成像，表明 Plk1 对于胚胎发育过程中进入有丝分裂至关重要。Plk1 突变体细胞表现出有丝分裂的不准确性，例如异常中心体、不规则纺锤体组装、染色体高度浓缩和染色体臂分离失败。因此，Plk1 的耗竭导致有丝分裂停滞，并最终在受精后 6 天死亡。相比之下，Plk2 或 Plk3 突变体胚胎没有显示出任何明显的异常。用 Plk1 抑制剂 BI 2536 处理胚胎会导致有丝分裂受阻，而用 Plk1 突变体处理时则更为严重。最后，通过一种挽救 Plk1 突变体表型的测定，我们发现激酶结构域和 PBD 结构域对于 Plk1 在斑马鱼发育中的功能都是必需的。我们的研究表明 Plk1 是胚胎增殖所必需的，因为其活性对于有丝分裂的完整性至关重要。此外，我们的研究表明，斑马鱼将是验证抗有丝分裂药物的有效且经济的体内系统。
