We investigated whether the small litter size in the 129 inbred mouse strain results from a reduction in oocyte fertilizability. Sensitivity of the zona pellucida to α-chymotrypsin was examined for oocytes collected at 14 h (shortly after ovulation), 17 h, and 20 h after hCG injection. Passage of spermatozoa through the zona pellucida (using an in vitro fertilization (IVF) technique) and the de...

Using homologous recombination, we have previously produced male mice carrying a disruptive mutation (Acr-/-) in the acrosin gene. Although Acr-/- mouse sperm lacking the acrosin protease activity still penetrated the zona pellucida and fertilized the egg, the mutant sperm exhibited a delay in penetration of the zona pellucida solely at the early stages after insemination. To further elucidate ...

The acrosome reaction by spermatozoa is an indispensable prerequisite for fertilization, and zonae pellucidae of human oocytes induce this reaction in the human spermatozoa attached to them. Human spermatozoa can attach to the zona pellucida of hamster oocytes when the oocytes have been treated with trypsin. We examined whether or not trypsin-treated hamster zona pellucida induces the acrosome ...

Background: Before human MII oocytes are vitrified they are usually denuded from their cumulus cells. In this study we wanted to investigate the effects of an intact corona radiata on the vitrification and fertilization of human oocytes. Materials and Methods: The study comprised two different parts. In Part 1, 36 MII stage oocytes, from 6 patients, were randomly assigned into a control group, ...

The mammalian zona pellucida surrounding ovulated eggs mediates sperm binding at fertilization, provides a postfertilization block to polyspermy, and facilitates passage of pre-implantation embryos down the oviduct. Although the three zona proteins (ZP1, ZP2, ZP3) are well conserved, mammalian fertilization is relatively specific and human sperm do not bind to the mouse zona pellucida. There ar...

Background: To clarify the mechanism of sperm penetration through the zona pellucida, the flagellar force generated by a hyperactivated spermatozoon was evaluated using the resistive force theory applied to the hyperactivated flagellar waves that were obtained from the mammalian spermatozoa. Materials and Methods: The hydrodynamic calculation of the flagellar force of the activated (non-hyperac...

abstract background: for infertile women aged over 35 years, failure of the zp (zona pellucida) to rupture is believed to be associated with a decreased implantation rate in in vitro fertilization (ivf) or intra cytoplasmic sperm injection (icsi). objective: in this research, laser assisted hatching (lah) was offered to patients with advanced maternal age to evaluate a possible benefit. materia...

Background: In spite of the great advances in vitrification, the mechanism of embryo damage which occure in some cases and varies from one case to another case is not exactly understood. Since Zona pellucida has an important role on early embryonic development, the aim of the present study is to investigate the effect of vitrification on integrity of zona pellucida and surveillance of blastocys...

Abbreviations: ZP, zona pellucida; ZPG, ZP glycoprotein; VE, vitelline envelope; VEG, VE glycoprotein; mZP, mouse ZP; hZP, human ZP; SS, signal sequence; CTP, C-terminal propeptide; CFCS, consensus furin cleavage-site; TMD, transmembrane domain; ZPD, ZP domain; NTS, N-terminal subdomain; CTS, C-terminal subdomain; EHP, external hydrophobic patch; IHP, internal hydrophobic patch; CP, charged pat...

The zona pellucida contains three proteins (ZP1, ZP2, ZP3), the precursors of which possess signal peptides, 'zona' domains and short (9-15 residue) cytoplasmic tails downstream of a transmembrane domain. The ectodomains of ZP2 and ZP3 are sufficient to form the insoluble zona matrix and yet each protein traffics through oocytes without oligomerization. ZP2 and ZP3 were fluorescently tagged and...