All vertebrates have an egg shell that surrounds ovulated eggs and plays critical roles in gamete recognition. This extracellular matrix is known as the zona pellucida in eutherian mammals and consists of three glycoproteins, ZP1, ZP2 and ZP3 in the mouse. To investigate the role of ZP1 in fertilization and early development, we have used targeted mutagenesis in embryonic stem cells to create m...

Knowledge about the mechanism that establishes embryonic polarity is fundamental in understanding mammalian development. In re-addressing several controversial claims, we recently proposed a model in which mouse embryonic polarity is not specified until the blastocyst stage. Before fertilization, the fully differentiated oocyte has been characterized as "polarized," and we indeed observed that ...

To understand the pathogenesis of organ-specific autoimmune disease requires an appreciation of how the T cell-mediated inflammation is targeted, and how the organ function is compromised. In this study, autoantibody was documented to influence both of these parameters by modulating the distribution of T cell-mediated inflammation. The murine autoimmune ovarian disease is induced by immunizatio...

Binding of guinea-pig spermatozoa to the zona pellucida of homologous eggs has been reported to involve 'receptors' on the inner acrosomal membrane (Huang et al. 1981). These receptors can be blocked by sulphated polysaccharides such as fucoidan (Huang and Yanagimachi, 1984). The aims of the present investigation were to identify these putative zona receptors using 125I-fucoidan as a probe and ...

Rabbit zonae pellucidae were isolated using a modified technique of Dunbar et al. (1980). Zonae pellucidae were solubilized in saline phosphate buffer (pH 7.8) for 30 min at 70 degrees C. One dimensional SDS-PAGE analysis showed that zona pellucida is essentially composed of three major proteins with apparent molecular weights of 200 (275-165) kd, 100 (135-96) kd and 75 (96-51) kd. Preincubatio...

In the present study we used an empty zona pellucida derived from hatched blastocysts as an alternative source for embryo aggregation and compared results with the conventional microwell method. Denuded 4-cell stage porcine embryos were aggregated by introduction into an empty zona or placement within a concave microwell. The present study showed that although the rate of aggregate formation wa...

zona pellucida contains receptors for a variety of plant lectins, glycoproteins that bind to specific saccharide determinants (Oikawa, Yanagimachi & Nicol¬ son, 1973; Oikawa, Nicolson & Yanagimachi, 1974; Nicolson, Yanagimachi & Yanagimachi, 1975). Some of these lectins can bind to the zona pellucida and induce egg agglutination and/or cause changes in the ability of the exterior region of the ...

Recent advances in many areas of reproductive technology, such as intracytoplasmic sperm injection (ICSI) and other forms of assisted fertilization, have been rapid. In many respects, these advances have outstripped our knowledge of the fundamental processes of human and animal sperm–egg interactions at fertilization. One of the major unresolved issues is the identity of the complementary molec...

the aim of this study was to examine the possible morphological and morphometric changes resulting from vitrification of embryos at the cleavage stage. in this study, 30 mice early-cleavage embryos at different stages of cleavage, resulting from in vitro fertilization (ivf) techniques, were examined before and after vitrification. digital images were taken from embryos before and after vitrific...