introduction: the incidence of sperm and oocyte premature chromosome condensation (pcc) in the failed fertilized oocytes that were taken after routine in viro fertilization (ivf) and intracytoplasmic sperm injection (icsi) programs were investigated. materials and methods: in this study, 364 air-dried preparations of failed fertilized oocytes after either ivf or ocsi procedures were analyzed. t...

Little is known about the composition and function of mammalian cortical granules. In this study, lectins were used as tools to: (1) estimate the number and molecular weight of glycoconjugates in hamster cortical granules and show what sugars are associated with each glycoconjugate; (2) identify cortical granule components that remain associated with the oolemma, cortical granule envelope, and/...

The sperm cell has a characteristic polarized morphology and its surface is also highly differentiated into different membrane domains. Junctional protein ring structures seal the surface of the mid-piece from the head and the tail respectively and probably prevent random diffusion of membrane molecules over the protein rings. Despite the absence of such lateral diffusion-preventing structures,...

Our objective was to identify any changes that occur in the composition of the porcine zona pellucida during development of the 2- to 4-cell embryo from the oocyte. Oocytes, unfertilized eggs and single and 2- to 4-cell embryos have been recovered surgically and their zonae pellucidae 125I-labelled and analysed individually by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE...

Maturation and fertilization of the starfish oocyte are putative calcium-dependent events. We have investigated the spatial distribution and temporal dynamics of this calcium dependence in single oocytes of Asterias forbesi. We used the calcium photoprotein, aequorin, in conjunction with a microscope-photomultiplier and microscope-image intensifier. Surprisingly, in contrast to earlier work wit...

For mammalian spermatozoa to exhibit the ability to bind the zona pellucida (ZP) they must undergo three distinct phases of maturation, namely, spermatogenesis (testis), epididymal maturation (epididymis) and capacitation (female reproductive tract). An impressive array of spermatozoa surface remodeling events accompany these phases of maturation and appear critical for recognition and adhesion...

BACKGROUND Although irregularities in human zona pellucida (ZP) morphology are well described, there is scant literature on the clinical significance of ZP dysmorphology. We, therefore, designed a retrospective cohort trial of ZP dysmorphology to assess the clinical significance of ZP dysmorphology and its affect on IVF outcome. Over the same time period a random sample of 77 cycles of 77 subje...

This presentation deals with assays based on in vitro fertilization (IVF) and related techniques such as zona pellucida (ZP) binding assays and oocyte penetration tests. These types of assays have been developed for several species of domestic animals. A description of the assays and how they have been performed in domestic animals, as well as data on the correlation between the results of assa...

BACKGROUND Oocyte cortical granules are important in the fertilization of numerous species including mammals. Relatively little is known about the composition, migration, and pre-fertilization release of mammalian oocyte cortical granules. RESULTS Results obtained with confocal scanning laser microscopy indicated that mouse oocytes have at least two populations of cortical granules, one that ...

The presence of the zona pellucida has been perceived as a requirement for the oviductal transfer of cloned embryos at early stages of development while protecting the embryo from an immune system response. We hypothesized that steroid hormone therapy could reduce a potential cellular immune response after the transfer of zona-free cloned embryos into the oviduct of recipient female goats. In E...