title: Cell cycle timing regulation during asynchronous divisions of the early C. elegans embryo.
abstract: A fundamental question in developmental biology is how different cell lineages acquire different cell cycle durations. With its highly stereotypical asymmetric and asynchronous cell divisions, the early Caenorhabditis elegans embryo provides an ideal system to study lineage-specific cell cycle timing regulation during development, with high spatio-temporal resolution. The first embryonic division is asymmetric and generates two blastomeres of different sizes (AB>P1) and developmental potentials that divide asynchronously, with the anterior somatic blastomere AB dividing reproducibly two minutes before the posterior germline blastomere P1. The evolutionarily conserved PAR proteins (abnormal embryonic PARtitioning of cytoplasm) regulate all of the asymmetries in the early embryo including cell cycle asynchrony between AB and P1 blastomeres. Here we discuss our current understanding and open questions on the mechanism by which the PAR proteins regulate asynchronous cell divisions in the early C. elegans embryo.
authors.affiliation: Institut Jacques Monod, CNRS, Université Paris Diderot, Bâtiment Buffon 15, Rue Hélène Brion, 75205 Paris Cedex 13, France.
authors.forename: N
authors.initials: N
authors.lastname: Tavernier
authors.affiliation: Cell Division and Differentiation Laboratory, Institute of Research in Immunology and Cancer, Université de Montréal, Montréal, Québec, Canada H3T 1J4; Department of Pathology and Cell Biology, Université de Montréal, Montréal, Québec, Canada H3T 1J4.
authors.forename: J C
authors.initials: JC
authors.lastname: Labbé
authors.affiliation: Institut Jacques Monod, CNRS, Université Paris Diderot, Bâtiment Buffon 15, Rue Hélène Brion, 75205 Paris Cedex 13, France. Electronic address: lionel.pintard@ijm.fr.
authors.forename: L
authors.initials: L
authors.lastname: Pintard
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000502:physiology; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology*; D059447:Cell Cycle Checkpoints / Q000502:physiology*; D002455:Cell Division; D004625:Embryo, Nonmammalian / Q000166:cytology* / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins
keywords: Asymmetric cell division; Cell cycle progression; Embryonic development; Mitosis; PAR protein-dependent polarization; Polo kinase