BACKGROUND Failures in expression of zona proteins correlate to subfertility in animals. Low expression of the zona proteins by the growing human oocyte may indicate reduced developmental potential. Therefore, we non-invasively analysed the thickness and the structure of the zona pellucida (ZP) of human oocytes with respect to embryo fate after ICSI. METHODS Retardance magnitude and thickness...

1 The avian perivitelline layer, an extracellular matrix homologous to the zona pellucida 2 of mammalian oocytes, is composed mainly by zona pellucida gene family glycoproteins. 3 Our previous studies in Japanese quail have demonstrated that the matrix's components, 4 ZP3 and ZPD, are synthesized in ovarian granulosa cells. Another component, ZP1, is 5 synthesized in the liver. Recently, we dem...

BACKGROUND Fertilization in mammals comprises the sequential interactions of the sperm with the cumulus oophorus, zona pellucida, and oocyte plasma membrane. Here we investigate proteasome activity in human sperm and its possible involvement during the fertilization process. METHODS Proteasome activity was measured in intact sperm and in sperm extracts using the fluorogenic substrate Suc-Leu-...

STUDY QUESTION Does laser-assisted zona thinning of cleavage stage mouse embryos facilitate hatching in vitro? SUMMARY ANSWER No, unlike laser zona opening, zona thinning does not facilitate embryo hatching. WHAT IS KNOWN ALREADY Artificial opening of the zona pellucida facilitates hatching of mouse and human embryos. Laser-assisted zona thinning has also been used for the purpose of assist...

We developed a highly-functional untethered on-chip robot for cell handling and micro-knife made by Si to cut zona pellucida of oocyte. The on-chip robot has a gripping mechanism which can grasp a cell or micro-object with sufficient power. The position and handling force of the robot are controlled independently by the magnetic force. The permanent magnets and electrical magnet are assembled t...

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. METHODS The study comprised two different parts. In Part 1, 36 MII stage oocytes, from 6 patients, were randomly assigned into a control group, a group of vit...

Characterization and classification of human zona pellucida glycoproteins is essential to understand the functions of these components during fertilization. To achieve this, antibodies were raised in rabbits against recombinant non-human primate [Bonnet Monkey (Macaca radiata)] zona pellucida proteins, bmZP1, bmZP2 and bmZP3 expressed in Escherichia coli. Antibodies against the three recombinan...

When proacrosin from mouse epididymal spermatozoa was activated a single form of acrosin was produced. The enzyme was isolated by gel filtration followed by affinity chromatography using Sepharose-4B linked to an acrosin inhibitor p-(p'-aminophenoxypropoxy)benzamidine. The molecular weight of partly purified acrosin was 53 000 by gel filtration, and of the pure enzyme 39 000 by SDS-polyacrylami...

It is generally accepted that the hatching of mouse blastocysts is accompanied by regional dissolution of the zona pellucida by a trypsin-like proteinase synthesized in trophectoderm cells (Perona and Wassarman, 1986; Hogan et al., 1994), and trophectoderm cells protrude from the dissolved hole of the zona pellucida (Orsini and McLaren, 1967; McLaren, 1970; Niimura and Fujii, 1997). Then a slit...