title: Zyg-11 and cul-2 regulate progression through meiosis II and polarity establishment in C. elegans.
abstract: The mechanisms that ensure coupling between meiotic cell cycle progression and subsequent developmental events, including specification of embryonic axes, are poorly understood. Here, we establish that zyg-11 and the cullin cul-2 promote the metaphase-to-anaphase transition and M phase exit at meiosis II in Caenorhabditis elegans. Our results indicate that ZYG-11 acts with a CUL-2-based E3 ligase that is essential at meiosis II and that functions redundantly with the anaphase-promoting complex/cyclosome at meiosis I. Our data also indicate that delayed M phase exit in zyg-11(RNAi) embryos is due to accumulation of the B type cyclin CYB-3. We demonstrate that PAR proteins and P granules become polarized in an inverted manner during the meiosis II delay resulting from zyg-11 or cul-2 inactivation, and that zyg-11 and cul-2 can regulate polarity establishment independently of a role in cell cycle progression. Furthermore, we find that microtubules appear dispensable for ectopic polarity during the meiosis II delay in zyg-11(RNAi) embryos, as well as for AP polarity during the first mitotic cell cycle in wild-type embryos. Our findings suggest a model in which a CUL-2-based E3 ligase promotes cell cycle progression and prevents polarity establishment during meiosis II, and in which the centrosome acts as a cue to polarize the embryo along the AP axis after exit from the meiotic cell cycle.
authors.affiliation: ISREC (Swiss Institute for Experimental Cancer Research Boveresses, CH-1066 Epalinges/Lausanne, Switzerland.
authors.forename: Rémi
authors.initials: R
authors.lastname: Sonneville
authors.forename: Pierre
authors.initials: P
authors.lastname: Gönczy
mesh_terms: D000818:Animals; D015415:Biomarkers; D019521:Body Patterning; D017173:Caenorhabditis elegans / Q000196:embryology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D016764:Cell Polarity; D044842:Cullin Proteins / Q000235:genetics / Q000378:metabolism*; D019926:Cyclin B / Q000235:genetics / Q000378:metabolism*; D056744:Cyclin B1; D003599:Cytoskeleton / Q000378:metabolism; D005260:Female; D008540:Meiosis / Q000502:physiology*; D008870:Microtubules / Q000378:metabolism; D009024:Morphogenesis; D009687:Nuclear Proteins / Q000378:metabolism; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D015415:Biomarkers; C491028:CYB-3 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; D044842:Cullin Proteins; D019926:Cyclin B; D056744:Cyclin B1; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; C491027:cul-2 proteins, C elegans; C454942:zyg-11 protein, C elegans