Document Detail


Meiosis-associated calcium waves in ascidian oocytes are correlated with the position of the male centrosome.
MedLine Citation:
PMID:  11108550     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We have used confocal microscopy to measure calcium waves and examine the distribution of tubulin in oocytes of the ascidian Ciona intestinalis during meiosis. We show that the fertilisation calcium wave in these oocytes originates in the vegetal pole. The sperm penetration site and female meiotic apparatus are found at opposite poles of the oocyte at fertilisation, confirming that C. intestinalis sperm enter in the vegetal pole of the oocyte. Following fertilisation, ascidian oocytes are characterised by repetitive calcium waves. Meiosis I-associated waves originate at the vegetal pole of the oocyte, and travel towards the animal pole. In contrast, the calcium waves during meiosis II initiate at the oocyte equator, and cross the oocyte cytoplasm perpendicular to the point of emission of the polar body. Immunolocalisation of tubulin during meiosis II reveals that the male centrosome is also located between animal and vegetal poles prior to initiation of the meiosis II-associated calcium waves, suggesting that the male centrosome influences the origin of these calcium transients. Ascidians are also characterised by an increase in sensitivity to intracellular calcium release after fertilisation. We show that this is not simply an effect of oocyte activation. The data strongly suggest a role for the male centrosome in controlling the mechanism and localisation of post-fertilisation intracellular calcium waves.
Authors:
M Wilding; M Marino; V Monfrecola; B Dale
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Zygote (Cambridge, England)     Volume:  8     ISSN:  0967-1994     ISO Abbreviation:  Zygote     Publication Date:  2000 Nov 
Date Detail:
Created Date:  2001-03-12     Completed Date:  2001-05-31     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  9309124     Medline TA:  Zygote     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  285-93     Citation Subset:  IM    
Affiliation:
Dipartimento Clinica di Emergenza Ginecologica e Ostetrica e Medicina della Riproduzione, Azienda Universitaria Policlinico, Università degli Studi Federico II, Naples, Italy. cocco.lone@libero.it
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MeSH Terms
Descriptor/Qualifier:
Animals
Calcium / physiology
Calcium Signaling / physiology*
Centrosome / physiology*,  ultrastructure*
Ciona intestinalis
Female
Male
Meiosis
Metaphase
Oocytes / cytology*,  drug effects,  physiology*
Sperm-Ovum Interactions
Spermatozoa / physiology
Tissue Extracts / pharmacology
Tubulin / analysis,  physiology
Chemical
Reg. No./Substance:
0/Tissue Extracts; 0/Tubulin; 7440-70-2/Calcium

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


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