title: Inhibition of Plk1 induces mitotic infidelity and embryonic growth defects in developing zebrafish embryos.
abstract: 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.
authors.affiliation: 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.
authors.forename: Kilhun
authors.initials: K
authors.lastname: Jeong
authors.forename: Jae-Yeon
authors.initials: JY
authors.lastname: Jeong
authors.forename: Hae-Ock
authors.initials: HO
authors.lastname: Lee
authors.forename: Eunhee
authors.initials: E
authors.lastname: Choi
authors.forename: Hyunsook
authors.initials: H
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D017209:Apoptosis; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D049109:Cell Proliferation; D020090:Chromosome Segregation / Q000187:drug effects; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006657:Histones / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D007700:Kinetics; D018715:Microscopy, Video / Q000379:methods; D008938:Mitosis / Q000187:drug effects; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D011621:Pteridines / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish / Q000196:embryology / Q000235:genetics; D029961:Zebrafish Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D000097869:Polo-Like Kinase 1
chemical_list: D018797:Cell Cycle Proteins; D049452:Green Fluorescent Proteins; D006657:Histones; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D011621:Pteridines; D029961:Zebrafish Proteins; D000097869:Polo-Like Kinase 1; C518477:BI 2536