The ultrastructural localization of mobilizable Ca2+ in different subcellular compartments of human oocytes and preimplantation embryos was studied using the potassium-pyroantimonate technique and transmission electron microscopy; the specificity was confirmed by chelation experiments and X-ray microanalysis. In unfertilized oocytes, Ca2+ was detected in small vesicles beneath the plasma membra...

Jürgen Habermas is regarded as a central bioconservative commentator in the debate on the ethics of human prenatal genetic manipulations. While his main work on this topic, The Future of Human Nature, has been widely examined in regard to his position on prenatal genetic enhancement, his arguments regarding prenatal genetic therapeutic interventions have for the most part been overlooked. In th...

Conflicting data still exist regarding the extent of paternal pronuclear DNA demethylation in one cell-stage mammalian embryos. Demethylation of paternal pronuclear DNA was observed in in vivo produced porcine zygotes, whereas in vitro produced embryos do not show any or only weak paternal genome demethylation. In our experiments, we have used and compared two in vitro techniques commonly used ...