The objective was to determine whether aging of sperm caused by incubation at normothermic (38.5 C) or heat shock (40 C) temperatures for 4 h prior to oocyte insemination affects sperm motility, fertilizing ability, competence of the resultant embryo to develop to the blastocyst stage and blastocyst sex ratio. In the first experiment, the percent of sperm that were motile was reduced by aging (...

In mammalian reproductive tract, the oviduct secretes huge number of growth factors and cytokines that create an optimal micro-environment for the initial stages of preimplantation embryos. Secretion of these growth factors is stage-specific. Among them, VEGF is a potent mitogen for vascular endothelium and stimulates vascular permeability. Apart from angiogenesis, VEGF in the oviduct may be in...

BACKGROUND The aim of this study was to examine whether the integrity rate of pronuclei, after cryopreservation of pronuclear zygotes, could be a predictor of future embryo development and implantation. METHODS Two-pronuclei stage zygotes (n = 862) were cryopreserved by aseptic rapid freezing in 15% ethylene glycol + 15% DMSO + 0.2 M sucrose with a 4-step exposure in 12% (v:v), 25, 50 and 100...

Oocytes inseminated by intracytoplasmic sperm injection using fresh ejaculated or freeze-dried rhesus macaque sperm showed similar activation, sperm aster assembly, and male-female pronuclear apposition rates.

Previously, we found that the growth arrest-specific gene 6 (Gas6) is more highly expressed in germinal vesicle (GV) oocytes than in metaphase II (MII) oocytes using annealing control primer (ACP)-PCR technology. The current study was undertaken to investigate the role of Gas6 in oocyte maturation and fertilization using RNA interference (RNAi). Interestingly, despite the specific and marked de...