title: Sustained centrosome-cortical contact ensures robust polarization of the one-cell C. elegans embryo.
abstract: In C. elegans, the anterior-posterior axis is established at the one-cell stage when the embryo polarizes along its long axis. One model suggests that a cue from the centrosome triggers symmetry breaking and is then dispensable for further steps in the process. In the absence of the initial centrosome cue, a redundant mechanism, reliant on the centrosome's microtubules, can polarize the cell. Despite this model, data from multiple sources suggest that direct centrosome-contact with the cortex may play a role in ensuring robust polarization. Some of this past work includes analysis of pam-1 mutants, which lack a functional puromycin-sensitive aminopeptidase and have aberrant centrosome positioning and variable polarization defects. To better understand the role of centrosome dynamics in polarization, we looked in detail at centrosome behavior in relation to key polarity landmarks in pam-1 mutants as well as those lacking cortical flows. We provide evidence for a model in which sustained direct contact between the centrosome and the cortex acts to reinforce both the actomyosin and the microtubule-dependent pathways. This contact is necessary for polarization when flows are inhibited.
authors.affiliation: Ursinus College, Department of Biology, Collegeville, PA 19426, United States. Electronic address: dom.sat@hotmail.com.
authors.forename: Dominique M
authors.initials: DM
authors.lastname: Saturno
authors.affiliation: Ursinus College, Department of Biology, Collegeville, PA 19426, United States. Electronic address: castoanzo@berkeley.edu.
authors.forename: Dominic T
authors.initials: DT
authors.lastname: Castanzo
authors.affiliation: Ursinus College, Department of Biology, Collegeville, PA 19426, United States. Electronic address: margarcw@gmail.com.
authors.forename: Margaret
authors.initials: M
authors.lastname: Williams
authors.affiliation: Ursinus College, Department of Biology, Collegeville, PA 19426, United States. Electronic address: deparikh@ursinus.edu.
authors.forename: Devayu A
authors.initials: DA
authors.lastname: Parikh
authors.affiliation: Ursinus College, Department of Biology, Collegeville, PA 19426, United States. Electronic address: ejaeger@ursinus.edu.
authors.forename: Eva C
authors.initials: EC
authors.lastname: Jaeger
authors.affiliation: Ursinus College, Department of Biology, Collegeville, PA 19426, United States. Electronic address: rlyczak@ursinus.edu.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Lyczak
mesh_terms: D000205:Actomyosin / Q000378:metabolism*; D000626:Aminopeptidases / Q000235:genetics; D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D017173:Caenorhabditis elegans / Q000196:embryology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D016764:Cell Polarity / Q000235:genetics*; D018385:Centrosome / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000235:genetics; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: D029742:Caenorhabditis elegans Proteins; C480837:NMY-2 protein, C elegans; D034741:RNA, Small Interfering; D000205:Actomyosin; D000626:Aminopeptidases; C023191:PepT tripeptidase; C025579:enkephalin degrading enzyme; D018995:Myosin Heavy Chains
keywords: Anterior-posterior axis; C. elegans; Centrosome; Polarity; Puromycin-sensitive aminopeptidase