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Dynamic analysis of Ca²+ level during bovine oocytes maturation and early embryonic development.

Liang SL, Zhao QJ, Li XC, Jin YP, Wang YP, Su XH, Guan WJ, Ma YH - J. Vet. Sci. (2011)

Bottom Line: However, Ca(2+) was distributed in the donor nucleus at 10 h and it was distributed throughout the blastomere in the 2-8 cell embryos.In this study, Ca(2+) showed significant fluctuations with regularity of IVF and SCNT groups, but PA did not.Systematic investigation of the Ca(2+) location and distribution changes during oocyte maturation and early embryo development processes should facilitate a better understanding of the mechanisms involved in oocyte maturation, reconstructed embryo activation and development, ultimately improving the reconstructed embryo development rate.

View Article: PubMed Central - PubMed

Affiliation: College of Veterinary Medicine, Northwest Agriculture and Forestry University, Yangling 712100, China.

ABSTRACT
Mammalian oocyte maturation and early embryo development processes are Ca(2+)-dependent. In this study, we used confocal microscopy to investigate the distribution pattern of Ca(2+) and its dynamic changes in the processes of bovine oocytes maturation, in vitro fertilization (IVF), parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) embryo development. During the germinal vesicle (GV) and GV breakdown stage, Ca(2+) was distributed in the cortical ooplasm and throughout the oocytes from the MI to MII stage. In IVF embryos, Ca(2+) was distributed in the cortical ooplasm before the formation of the pronucleus. In 4-8 cell embryos and morulas, Ca(2+) was present throughout the blastomere. In PA embryos, Ca(2+) was distributed throughout the blastomere at 48 h, similar to in the 4-cell and 8-cell phase and the morula. At 6 h after activation, there was almost no distribution of Ca(2+) in the SCNT embryos. However, Ca(2+) was distributed in the donor nucleus at 10 h and it was distributed throughout the blastomere in the 2-8 cell embryos. In this study, Ca(2+) showed significant fluctuations with regularity of IVF and SCNT groups, but PA did not. Systematic investigation of the Ca(2+) location and distribution changes during oocyte maturation and early embryo development processes should facilitate a better understanding of the mechanisms involved in oocyte maturation, reconstructed embryo activation and development, ultimately improving the reconstructed embryo development rate.

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Ca2+ distribution in bovine oocytes during different phases of in vitro maturation. A: Germinal vesicle (GV) stage; B and C: Germinal vesicle breakdown (GVBD) stage; D: MI stage; E: End of MI stage; F: MII stage.
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Figure 1: Ca2+ distribution in bovine oocytes during different phases of in vitro maturation. A: Germinal vesicle (GV) stage; B and C: Germinal vesicle breakdown (GVBD) stage; D: MI stage; E: End of MI stage; F: MII stage.

Mentions: During the GV stage, Ca2+ was primarily distributed in the cortical ooplasm region and the fluorescence intensity was weak, while there was almost no distribution in other regions (Fig. 1A). In the GVBD stage (after 8 h of IVM), Ca2+ was still distributed in the cortical ooplasm region and tended to diffuse to the center of cells (Figs. 1B and C). From the MI to MII stage, Ca2+ was distributed throughout the oocytes. In the MI stage (after 14 h of IVM), the fluorescence intensity of the cortical ooplasm region was stronger than in the cytoplasmic area (Fig. 1D), while at the end of the MI stage Ca2+ in the chromosome area was higher (Fig. 1E), while there was stronger fluorescence in the polar bodies in the MII stage (Fig. 1F).


Dynamic analysis of Ca²+ level during bovine oocytes maturation and early embryonic development.

Liang SL, Zhao QJ, Li XC, Jin YP, Wang YP, Su XH, Guan WJ, Ma YH - J. Vet. Sci. (2011)

Ca2+ distribution in bovine oocytes during different phases of in vitro maturation. A: Germinal vesicle (GV) stage; B and C: Germinal vesicle breakdown (GVBD) stage; D: MI stage; E: End of MI stage; F: MII stage.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3104167&req=5

Figure 1: Ca2+ distribution in bovine oocytes during different phases of in vitro maturation. A: Germinal vesicle (GV) stage; B and C: Germinal vesicle breakdown (GVBD) stage; D: MI stage; E: End of MI stage; F: MII stage.
Mentions: During the GV stage, Ca2+ was primarily distributed in the cortical ooplasm region and the fluorescence intensity was weak, while there was almost no distribution in other regions (Fig. 1A). In the GVBD stage (after 8 h of IVM), Ca2+ was still distributed in the cortical ooplasm region and tended to diffuse to the center of cells (Figs. 1B and C). From the MI to MII stage, Ca2+ was distributed throughout the oocytes. In the MI stage (after 14 h of IVM), the fluorescence intensity of the cortical ooplasm region was stronger than in the cytoplasmic area (Fig. 1D), while at the end of the MI stage Ca2+ in the chromosome area was higher (Fig. 1E), while there was stronger fluorescence in the polar bodies in the MII stage (Fig. 1F).

Bottom Line: However, Ca(2+) was distributed in the donor nucleus at 10 h and it was distributed throughout the blastomere in the 2-8 cell embryos.In this study, Ca(2+) showed significant fluctuations with regularity of IVF and SCNT groups, but PA did not.Systematic investigation of the Ca(2+) location and distribution changes during oocyte maturation and early embryo development processes should facilitate a better understanding of the mechanisms involved in oocyte maturation, reconstructed embryo activation and development, ultimately improving the reconstructed embryo development rate.

View Article: PubMed Central - PubMed

Affiliation: College of Veterinary Medicine, Northwest Agriculture and Forestry University, Yangling 712100, China.

ABSTRACT
Mammalian oocyte maturation and early embryo development processes are Ca(2+)-dependent. In this study, we used confocal microscopy to investigate the distribution pattern of Ca(2+) and its dynamic changes in the processes of bovine oocytes maturation, in vitro fertilization (IVF), parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) embryo development. During the germinal vesicle (GV) and GV breakdown stage, Ca(2+) was distributed in the cortical ooplasm and throughout the oocytes from the MI to MII stage. In IVF embryos, Ca(2+) was distributed in the cortical ooplasm before the formation of the pronucleus. In 4-8 cell embryos and morulas, Ca(2+) was present throughout the blastomere. In PA embryos, Ca(2+) was distributed throughout the blastomere at 48 h, similar to in the 4-cell and 8-cell phase and the morula. At 6 h after activation, there was almost no distribution of Ca(2+) in the SCNT embryos. However, Ca(2+) was distributed in the donor nucleus at 10 h and it was distributed throughout the blastomere in the 2-8 cell embryos. In this study, Ca(2+) showed significant fluctuations with regularity of IVF and SCNT groups, but PA did not. Systematic investigation of the Ca(2+) location and distribution changes during oocyte maturation and early embryo development processes should facilitate a better understanding of the mechanisms involved in oocyte maturation, reconstructed embryo activation and development, ultimately improving the reconstructed embryo development rate.

Show MeSH
Related in: MedlinePlus