The present study aimed to establish an efficient system for bovine embryo production by in vitro fertilization (IVF) that can achieve stable normal fertilization and blastocyst developmental rates in any bull without optimization of the sperm concentration in IVF medium. We examined the effects of a PHE mixture (20 μM D-penicillamine, 10 μM hypotaurine and 1 μM epinephrine), theophylline (2.5 ...

The percentages of sperm motility and normal acrosome on the liquid boar semen diluted and preserved at 4°C with lactose hydrate, egg yolk and N-acetyl-D-glucosamine (LEN) diluent were significant differences according to preservation day and incubation time, respectively. The sperm motility steadily declined from 96.9% at 0.5 h incubation to 78.8% at 6 h incubation at 1 day of preservation. Ho...

Oocytes of LT/Sv mice have anomalous cytoplasmic and nuclear maturation. Here, we show that in contrast to the oocytes of wild-type mice, a significant fraction of LT/Sv oocytes remains arrested at the metaphase of the first meiotic division and is unable to undergo sperm-induced activation when fertilized 15 hours after the resumption of meiosis. We also show that LT/Sv oocytes experimentally ...

Fertilization in vivo is a complex process consisting of six steps, namely, penetration of the cumulus complex, binding of the sperm to the zona pellucida, fusion of oocyte and sperm, oocyte activation, sperm remodelling, and formation of the pronuclei. Since ICSI bypasses the first three steps any problem related to fertilization failure after ICSI arises from oocyte activation onwards. Accord...

Recognition between sperm and the egg surface marks the beginning of life in all sexually reproducing organisms. This fundamental biological event depends on the species-specific interaction between rapidly evolving counterpart molecules on the gametes. We report biochemical, crystallographic, and mutational studies of domain repeats 1-3 of invertebrate egg coat protein VERL and their interacti...

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...

Mammalian sperm must hyperactivate in order to fertilize oocytes. Hyperactivation is characterized by highly asymmetrical flagellar bending. It serves to move sperm out of the oviductal reservoir and to penetrate viscoelastic fluids, such as the cumulus matrix. It is absolutely required for sperm penetration of the oocyte zona pellucida. In order for sperm to hyperactivate, cytoplasmic Ca level...

Multipurpose prevention technologies (MPTs) that simultaneously prevent sexually transmitted infections (STIs) and unintended pregnancy are a global health priority. Combining chemical and physical barriers offers the greatest potential to design effective MPTs, but integrating both functional modalities into a single device has been challenging. Here we show that drug-eluting fiber meshes desi...