The universal signal for egg activation at fertilization is a rise in cytoplasmic Ca(2+) with defined spatial and temporal kinetics. Mammalian and amphibian eggs acquire the ability to produce such Ca(2+) signals during a maturation period that precedes fertilization and encompasses resumption of meiosis and progression to metaphase II. In Xenopus, immature oocytes produce fast, saltatory Ca(2+...

in this paper we investigate a new notion of bases in hilbert spaces and similarto fusion frame theory we introduce fusion bases theory in hilbert spaces. we also introducea new denition of fusion dual sequence associated with a fusion basis and show that theoperators of a fusion dual sequence are continuous projections. next we dene the fusionbiorthogonal sequence, bessel fusion basis, hilbe...

Fusion of large and small karyoplasts produced from metaphase II mouse oocytes with interphase blastomeres from 2-cell and 8-cell embryos (volume ratio of partners, 1:1) results in premature chromosome condensation (PCC) of the interphase nucleus in the majority of the fusion products (hybrids). Fused under the same experimental protocol, oocyte-derived cytoplasts also induce PCC of the blastom...

BACKGROUND Mammalian sperm-oocyte interaction at fertilization involves several combined interactions between integrins on the oocyte and integrin ligands (disintegrins) on the sperm. Recent research has indicated the ability of peptides containing the RGD sequence that characterized several sperm disintegrins, to induce intracellular Ca2+ transients and to initiate parthenogenetic development ...

One of the several factors that contribute to the low efficiency of mammalian somatic cloning is poor fusion between the small somatic donor cell and the large recipient oocyte. This study was designed to test phytohemagglutinin (PHA) agglutination activity on fusion rate, and subsequent developmental potential of cloned bovine embryos. The toxicity of PHA was established by examining its effec...

fertilization involves direct interaction of the sperm and oocyte, fusion of the cell membranes and :union: of male and female gamete genomes. the completion of this process and subsequent embryo development depend in part on the inherent integrity of the sperm dna. sperm genome quality has been emphasized for several years as playing a major role in early embryogenesis. there is clinical evide...

In mouse somatic cell nuclear transfer (SCNT), polyvinylpyrrolidone (PVP) is typically included in the nuclear donor injection medium. However, the cytotoxicity of PVP, which is injected into the cytoplasm of oocytes, has recently become a cause of concern. In the present study, we determined whether bovine serum albumin deionized with an ion-exchange resin treatment (d-BSA) was applicable to t...

The inheritance of maternal factors in oocytes plays a crucial role in development, particularly in non-mammalian species, where asymmetric segregation of developmental factors among early blastomeres regulates early patterning of the embryo. Whereas this role is less important in mammals, a number of studies have shown that maternal inheritance is equally critical for regulating development th...