FIND ARTICLE

THE ROLE OF CALCIUM IONS IN ACTIVATION OF THE MAMMALIAN EMBRYO DEVELOPMENT

Fertilization of a mouse oocyte triggers oscillations of the concentration of free calcium ions in ooplasm ([Ca2+] i ). Calcium oscillations are generated in a process involving inositol 1,4,5-triphosphate (IP 3 ) produced by phospholipase C zeta (PLC zeta), a sperm specific isoform of phospholipase C. Calcium transients last for several hours until the time of pronuclei formation. The ability to generate and sustain long-lasting oscillations of [Ca2+] i is developed in oocytes during meiotic maturation, i.e.

THE ROLE OF CYTOSTATIC ACTIVITY IN MEIOTIC MATURATION OF MAMMALIAN OOCYTES

Maturing vertebrate oocytes become arrested in metaphase of the second meiotic division. These oocytes are ovulated, and then can be activated by sperm or parthenogenetic stimulus. Metaphase arrest is mediated by the cytostatic activity – CSF, that prevents the inactivation of the major M-phase regulator i.e. CDK1-cyclin B kinase. CSF inactivation seems to be necessary for the completion of the second meiotic division and the initiation of the embryonic development. Analysis of amphibian oocyte maturation led to the discovery of factors crucial for the CSF activation.

The Editorial Board
Andrzej Łukaszyk - przewodniczący, Zofia Bielańska-Osuchowska, Szczepan Biliński, Mieczysław Chorąży, Aleksander Koj, Włodzimierz Korochoda, Leszek Kuźnicki, Aleksandra Stojałowska, Lech Wojtczak

Editorial address:
Katedra i Zakład Histologii i Embriologii Uniwersytetu Medycznego w Poznaniu, ul. Święcickiego 6, 60-781 Poznań, tel. +48 61 8546453, fax. +48 61 8546440, email: mnowicki@ump.edu.pl

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