the aim of this study was to compare the effect of time of parthenogenetic activation (22 hr versus 27 hr after in vitro maturation-ivm) on in vitro development of ovine oocytes using either single (ionomycin 5 ?m for 5 min or ethanol 7% for 7 min) or combined (ionomycin and ethanol with 6-dmap 2 mm for 3 hr) activation treatments. the abattoir-derived in vitro matured activated oocytes were cu...

background: the selection of pre-embryos for transferred is based on morphological appearance. but some poor quality cleaved embryos also can be cultured to the blastocyst stage and implanted. objective: to assess the clinical pregnancy outcomes of blastocyst transfer which developed from poor quality embryos. materials and methods: a total of 109 cleaved embryos with poor quality were cultured...

Prostaglandins participate in a variety of female reproductive processes, including ovulation, fertilization, embryo implantation and parturition. In particular, maternal prostacyclin (PGI(2)) is critical for embryo implantation and the action of PGI(2) is not mediated via its G-protein-coupled membrane receptor, IP, but its nuclear receptor, peroxisome-proliferator-activated receptor δ (PPARδ)...

Properties of uptake and exchange of L-methionine associated with the compartments of the blastocyst were examined in the mouse embryo. The inner cell mass (ICM) was derived from the 102 h blastocyst by immunosurgical procedures and studied in isolation. The ICM possessed strong exchange and efflux transport character. The Vmax of transport was about one-fifth that of the intact blastocyst, but...

UNLABELLED Blastocyst formation is essential for implantation and maintenance of pregnancy and is dependent on the expression and coordinated function of a series of proteins involved in establishing and maintaining the trans-trophectoderm ion gradient that enables blastocyst expansion. These consist of Na/K-ATPase, adherens junctions, tight junctions (TJ) and aquaporins (AQP). While their role...

Little information is available on perinatal outcome of cryopreserved day-7 blastocyst transfer. In the present report, perinatal outcomes for transfers of cryopreserved blastocysts by a vitrification method were examined with respect to the day of blastocyst expansion among on day 5, 6 or 7 before cryopreservation. We investigated 263 cycles of vitrified-warmed blastocyst stage embryo transfer...

OBJECTIVE To study the clinical outcomes of single frozen-thawed blastocyst transfer cycles according to the hatching status of frozen-thawed blastocysts. METHODS Frozen-thawed blastocysts were divided into three groups according to their hatching status as follows: less-than-expanded blastocyst (≤EdB), hatching blastocyst (HgB), and hatched blastocyst (HdB). The female age and infertility fa...

Embryo implantation is a highly orchestrated process that involves blastocyst-uterine interactions. This process is confined to a defined interval during gestation referred to as the "window of embryo implantation receptivity". In mice this receptive period is controlled by ovarian estrogen and involves a coordination of blastocyst adhesion competence and uterine receptivity. Mechanisms coordin...

An in vitro assay has been developed in order to examine the mechanism whereby the mouse blastocyst regulates embryonal carcinoma (EC). The assay measures the suppression of EC cell colony formation caused by exposure to the cavity of the blastocyst (i.e., blastocele), and the results are comparable to the previous results with blastocyst-mediated suppression of tumor formation for this same ce...

The aim of this study was to investigate the effects of donor cell passage, size and type on the development of nuclear transfer embryos. Porcine cumulus cells, fetal fibroblasts and oviductal epithelial cells from 1-2, 3-6 and 7-10 passages were used for the nuclear transfer. In the oocytes with the cumulus donor cells, fusion and cleavage rates of oocytes and cell numbers per blastocyst among...