Application of intracytoplasmic sperm injection to the embryo production in aged cows.

Reduction in oocyte quality is a major factor responsible for declining fertility associated with maternal aging in cows. The objective of the present study was to determine whether intracytoplasmic sperm injection (ICSI) could increase the efficiency of embryo production in older cows. We used cows aged 30 to 50 months or >120 months, which were defined as young or aged, respectively.

Prolonging hypothermic storage (4 C) of bovine embryos with fish antifreeze protein.

Embryos obtained via superovulation are necessary for mammalian artificial reproduction, and viability is a key determinant of success. Nonfreezing storage at 4 C is possible, but currently used storage solutions can maintain embryo viability for only 24-48 h. Here we found that 10 mg/ml antifreeze protein (AFP) dissolved in culture medium 199 with 20% (v/v) fetal bovine serum and 25 mM HEPES could keep bovine embryos alive for 10 days at 4 C.

A simple medium enables bovine embryos to be held for seven days at 4°C.

Cryopreservation methods using liquid nitrogen (LN(2)) for gametes and embryos are prevalent in mammalian artificial reproduction. However, the pregnancy rate from frozen embryos has not improved over the past two decades because freeze-thawing causes significant damage. The strict regulation of transportation of LN(2) containers by airlines also limits exchange between breeders.

Addition of erythrocytes to in vitro culture medium attenuates the detrimental effects of reactive oxygen species on bovine preimplantation embryo development.

Erythrocytes were recently found to improve the early development of mice embryos by their antioxidant effect. The purpose of the present study was to examine the effect of erythrocytes on the in vitro development of bovine in vitro fertilized (IVF) embryos in medium supplemented with reactive oxygen species (ROS). IVF embryos were cultured in CR1aa medium supplemented with oxidizing agents, 0.

Intrauterine administration of peripheral blood mononuclear cells enhances early development of the pre-implantation bovine embryo.

Intrauterine administration of peripheral blood mononuclear cells (PBMCs) prior to bovine embryo transfer (ET) was previously shown to improve the pregnancy rate. To better understand how PBMCs improve the pregnancy rate, we examined gene expression in the cells from uterine lumen and evaluated the morphology of bovine pre-attachment embryos in utero following intrauterine administration of PBMCs. On day 3 of the estrous cycle (day 0 = estrous), bovine PBMCs were isolated and suspended in RPMI 1640, and were incubated for 24 hr.

Comparison of early development in utero of cloned fetuses derived from bovine fetal fibroblasts at the G1 and G0/G1 phases.

In bovine somatic cell nuclear transfer (NT), embryos are more likely to develop to full term when they are derived from fibroblasts at the G1 phase instead of cells at the G0/G1 phase. To better understand the reason for this difference, we examined morphological development in the early pregnancy of NT embryos using G1 phase cells (G1-NT embryos) and G0/G1 phase cells (G0/G1-NT embryos). Blastocysts derived from G1 and G0/G1-NT embryos were transferred to recipient heifers, and the conceptuses at day 50 of gestation were retrieved non-surgically using prostaglandin F(2alpha) and oxytocin.

Administration of peripheral blood mononuclear cells into the uterine horn to improve pregnancy rate following bovine embryo transfer.

Embryo transfer (ET) has been used to improve reproductive efficiency and genetic make-up in bovine species. However, the success rate of ET has not been improved since its inception. Here we examined whether administration of autologous peripheral blood mononuclear cells (PBMCs) into the uterine horn can improve pregnancy rates following bovine ET.