spacer gif spacer gif spacer gif spacer gif spacer gif
 QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    


This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Roegiers, F.
Right arrow Articles by Sardet, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Roegiers, F.
Right arrow Articles by Sardet, C.
Social Bookmarking
 Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Development, Vol 121, Issue 10 3457-3466, Copyright © 1995 by Company of Biologists


JOURNAL ARTICLES

The sperm entry point defines the orientation of the calcium-induced contraction wave that directs the first phase of cytoplasmic reorganization in the ascidian egg

F Roegiers, A McDougall and C Sardet
URA 671 Biologie Cellulaire Marine, CNRS, Universite P. et M. Curie, Villefranche-sur-Mer, France.

Ascidians eggs are spawned with their cytoskeleton and organelles organized along a preexisting animal-vegetal axis. Fertilization triggers a spectacular microfilament-dependant cortical contraction that causes the relocalization of preexisting cytoplasmic domains and the creation of new domains in the lower part of the vegetal hemisphere. We have investigated the relationship between fertilization, the cortical contraction and the localization of cytoplasmic domains in eggs of the ascidian Phallusia mammillata. We have also examined the link between this first phase of ooplasmic segregation and the site of gastrulation. The cortical contraction was found to be initiated on the side of the egg where intracellular calcium is first released either by the entering sperm or by photolysis of caged InsP3. The cortical contraction carries the sperm nucleus towards the vegetal hemisphere along with a subcortical mitochondria-rich domain (the myoplasm). If the sperm enters close to the animal or vegetal poles the cortical contraction is symmetrical, travelling along the animal-vegetal axis. If the sperm enters closer to the equator, the contraction is asymmetrical and its direction does not coincide with the animal-vegetal axis. The direction of contraction defines an axis along which preexisting (such as the myoplasm) or newly created cytoplasmic domains are relocalized. Two microfilament-rich surface constrictions, the 'contraction pole' and the 'vegetal button' (which forms 20 minutes later), appear along that axis approximately opposite the site where the contraction is initiated. The contraction pole can be situated as much as 55 degrees from the vegetal pole, and its location predicts the site of gastrulation. It thus appears that in ascidian eggs, the organization of the egg before fertilization defines a 110 degrees cone centered around the vegetal pole in which the future site of gastrulation of the embryo will lie. The calcium wave and cortical contraction triggered by the entering sperm adjust the location of cytoplasmic domains along an axis within that permissive zone. We discuss the relation between that axis and the establishment of the dorsoventral axis in the ascidian embryo.
Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:


Home page
J. Cell Sci.Home page
M. Levasseur, M. Carroll, K. T. Jones, and A. McDougall
A novel mechanism controls the Ca2+ oscillations triggered by activation of ascidian eggs and has an absolute requirement for Cdk1 activity
J. Cell Sci., May 15, 2007; 120(10): 1763 - 1771.
[Abstract] [Full Text] [PDF]


Home page
DevelopmentHome page
C. R. Cowan and A. A. Hyman
Acto-myosin reorganization and PAR polarity in C. elegans
Development, March 15, 2007; 134(6): 1035 - 1043.
[Abstract] [Full Text] [PDF]


Home page
Physiol. Rev.Home page
M. Whitaker
Calcium at Fertilization and in Early Development
Physiol Rev, January 1, 2006; 86(1): 25 - 88.
[Abstract] [Full Text] [PDF]


Home page
JCBHome page
H. Parry, A. McDougall, and M. Whitaker
Microdomains bounded by endoplasmic reticulum segregate cell cycle calcium transients in syncytial Drosophila embryos
J. Cell Biol., October 10, 2005; 171(1): 47 - 59.
[Abstract] [Full Text] [PDF]


Home page
J. Cell Sci.Home page
F. Prodon, P. Dru, F. Roegiers, and C. Sardet
Polarity of the ascidian egg cortex and relocalization of cER and mRNAs in the early embryo
J. Cell Sci., June 1, 2005; 118(11): 2393 - 2404.
[Abstract] [Full Text] [PDF]


Home page
J. Cell Sci.Home page
M. Carroll, M. Levasseur, C. Wood, M. Whitaker, K. T. Jones, and A. McDougall
Exploring the mechanism of action of the sperm-triggered calcium-wave pacemaker in ascidian zygotes
J. Cell Sci., December 15, 2003; 116(24): 4997 - 5004.
[Abstract] [Full Text] [PDF]


Home page
DevelopmentHome page
C. Sardet, H. Nishida, F. Prodon, and K. Sawada
Maternal mRNAs of PEM and macho 1, the ascidian muscle determinant, associate and move with a rough endoplasmic reticulum network in the egg cortex
Development, December 1, 2003; 130(23): 5839 - 5849.
[Abstract] [Full Text] [PDF]


Home page
DevelopmentHome page
R. Dumollard, K. Hammar, M. Porterfield, P. J. Smith, C. Cibert, C. Rouviere, and C. Sardet
Mitochondrial respiration and Ca2+ waves are linked during fertilization and meiosis completion
Development, February 15, 2003; 130(4): 683 - 692.
[Abstract] [Full Text] [PDF]


Home page
Mol. Biol. CellHome page
G. FitzHarris, P. Marangos, and J. Carroll
Cell Cycle-dependent Regulation of Structure of Endoplasmic Reticulum and Inositol 1,4,5-Trisphosphate-induced Ca2+ Release in Mouse Oocytes and Embryos
Mol. Biol. Cell, January 1, 2003; 14(1): 288 - 301.
[Abstract] [Full Text]


Home page
J. Cell Sci.Home page
R. Dumollard and C. Sardet
Three different calcium wave pacemakers in ascidian eggs
J. Cell Sci., January 7, 2001; 114(13): 2471 - 2481.
[Abstract] [Full Text] [PDF]


Home page
J. Cell Sci.Home page
A McDougall, M Levasseur, A. O'Sullivan, and K. Jones
Cell cycle-dependent repetitive Ca(2+ )waves induced by a cytosolic sperm extract in mature ascidian eggs mimic those observed at fertilization
J. Cell Sci., January 10, 2000; 113(19): 3453 - 3462.
[Abstract] [PDF]


Home page
Hum ReprodHome page
C. Garello, H. Baker, J. Rai, S. Montgomery, P. Wilson, C.R. Kennedy, and G.M. Hartshorne
Pronuclear orientation, polar body placement, and embryo quality after intracytoplasmic sperm injection and in-vitro fertilization: further evidence for polarity in human oocytes?
Hum. Reprod., October 1, 1999; 14(10): 2588 - 2595.
[Abstract] [Full Text] [PDF]


Home page
DevelopmentHome page
F Roegiers, C Djediat, R Dumollard, C Rouviere, and C Sardet
Phases of cytoplasmic and cortical reorganizations of the ascidian zygote between fertilization and first division
Development, January 6, 1999; 126(14): 3101 - 3117.
[Abstract] [PDF]


Home page
DevelopmentHome page
L Alessa and D. Kropf
F-actin marks the rhizoid pole in living Pelvetia compressa zygotes
Development, January 1, 1999; 126(1): 201 - 209.
[Abstract] [PDF]


Home page
DevelopmentHome page
A McDougall and M Levasseur
Sperm-triggered calcium oscillations during meiosis in ascidian oocytes first pause, restart, then stop: correlations with cell cycle kinase activity
Development, January 11, 1998; 125(22): 4451 - 4459.
[Abstract] [PDF]


Home page
DevelopmentHome page
K Kyozuka, R Deguchi, T Mohri, and S Miyazaki
Injection of sperm extract mimics spatiotemporal dynamics of Ca2+ responses and progression of meiosis at fertilization of ascidian oocytes
Development, January 10, 1998; 125(20): 4099 - 4105.
[Abstract] [PDF]




© The Company of Biologists Ltd 1995