This study was designed to compare the efficiency of the Cryotop method and that of two methods that employ a micro volume air cooling (MVAC) device by analyzing the survival and development of bovine oocytes and blastocysts vitrified using each method. In experiment I, in vitro-matured (IVM) oocytes were vitrified using an MVAC device without direct contact with liquid nitrogen (LN2; MVAC grou...

Preimplantation development shifts from a maternal to embryonic programme rapidly after fertilization. Although the majority of oogenetic products are lost during the maternal to embryonic transition (MET), several do survive this interval to contribute directly to supporting preimplantation development. Embryonic genome activation (EGA) is characterized by the transient expression of several g...

The changes triggered by sperm-induced activation of oocytes, which are required for normal oocyte development, can be mediated by other agents, thereby inducing the parthenogenesis. In this study, we exposed porcine oocytes to 1 mM Ca-EDTA, a metal-ion chelator, at various intervals during 48 hr of in vitro maturation to determine the optimum period of Ca-EDTA treatment for parthenogenetic act...

BACKGROUND It is still debatable whether a full-thickness assisted hatching (AH) is better than the partial zona thinning. In this research, we used a mouse model to study the effect of partial and complete laser-AH on the rate of completely hatched blastocyst and their cell numbers. METHODS In experiment 1, mouse morulae had 0, 1, 2 or 3 full-thickness openings of 10 microns created in the z...

The purpose of this study is to develop a mouse sperm preservation method based on evaporative drying. Mouse sperm were evaporatively dried and stored at 4°C and ambient temperature for 3 months to 2 years. Upon rehydration, a single sperm was injected into a mature oocyte to develop into a blastocyst after culture or a live birth after embryo transfer to a recipient female. For the samples sto...

Previous studies showed that insulin promotes cell proliferation and morphological development of preimplantation mouse embryos. In this report, the receptor responsible for these actions and the cell populations that are affected were investigated. Insulin's 9% stimulation of blastocyst cell number was entirely due to a 23% increase in ICM cell number with an EC50 of 0.54 pM. This and the simi...

A comparison of the effects of replacing L -glutamine with either glycyl-L-glutamine or alanyl-L-glutamine in a KSOM-type medium on the development of mouse preimplantation embryos in vitro has been made. Alanyl-L-glutamine has no significant effect on the rates of blastocyst formation, onset or completion of hatching, and on the numbers of inner cell mass and trophectoderm cells that develop. ...

In this retrospective study on 1628 consecutive cycles performed during a period of 4 years, development in vitro is compared of embryos obtained after either conventional in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). At 39-42 h after insemination or injection, embryos obtained after ICSI were significantly (P < 0.01) further developed (mean cell number 3.48 +/- 0.03)...