Document Detail

A model for cleavage plane determination in early amphibian and fish embryos.
MedLine Citation:
PMID:  21055946     Owner:  NLM     Status:  MEDLINE    
Current models for cleavage plane determination propose that metaphase spindles are positioned and oriented by interactions of their astral microtubules with the cellular cortex, followed by cleavage in the plane of the metaphase plate [1, 2]. We show that in early frog and fish embryos, where cells are unusually large, astral microtubules in metaphase are too short to position and orient the spindle. Rather, the preceding interphase aster centers and orients a pair of centrosomes prior to nuclear envelope breakdown, and the spindle assembles between these prepositioned centrosomes. Interphase asters center and orient centrosomes with dynein-mediated pulling forces. These forces act before astral microtubules contact the cortex; thus, dynein must pull from sites in the cytoplasm, not the cell cortex as is usually proposed for smaller cells. Aster shape is determined by interactions of the expanding periphery with the cell cortex or with an interaction zone that forms between sister-asters in telophase. We propose a model to explain cleavage plane geometry in which the length of astral microtubules is limited by interaction with these boundaries, causing length asymmetries. Dynein anchored in the cytoplasm then generates length-dependent pulling forces, which move and orient centrosomes.
Martin Wühr; Edwin S Tan; Sandra K Parker; H William Detrich; Timothy J Mitchison
Related Documents :
12655596 - Microfilament and microtubule organization and dynamics in process extension by central...
10736206 - Bundling of microtubules in the growth cone induced by laminin.
7227036 - Structure of the mammalian kinetochore.
20519956 - Kl1 is a novel microtubule severing enzyme that regulates mitotic spindle architecture.
1522246 - The melanin-concentrating hormone system of the rat brain: an immuno- and hybridization...
7180316 - "de novo" formation of synapses by experimentally induced presynaptic dendrites in adul...
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2010-11-04
Journal Detail:
Title:  Current biology : CB     Volume:  20     ISSN:  1879-0445     ISO Abbreviation:  Curr. Biol.     Publication Date:  2010 Nov 
Date Detail:
Created Date:  2010-11-24     Completed Date:  2011-04-18     Revised Date:  2014-09-16    
Medline Journal Info:
Nlm Unique ID:  9107782     Medline TA:  Curr Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  2040-5     Citation Subset:  IM    
Copyright Information:
Copyright © 2010 Elsevier Ltd. All rights reserved.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Cell Division*
Centrosome / ultrastructure
Embryo, Nonmammalian / cytology*,  ultrastructure
Embryonic Development
Microtubules / ultrastructure
Models, Biological*
Spermatozoa / ultrastructure
Spindle Apparatus / metabolism,  ultrastructure
Xenopus laevis
Zebrafish / embryology
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Modulating neuronal activity produces specific and long-lasting changes in numerical competence.
Next Document:  WNT5A/JNK and FGF/MAPK pathways regulate the cellular events shaping the vertebrate limb bud.