OBJECTIVE It is not known whether progesterone, which plays a key role in establishing and maintaining pregnancy, acts directly on embryos or indirectly through the mother's reproductive tract. Since the physiological effects of progesterone are mediated by progesterone receptors (PR), the expression of PR during the preimplantation stages of pig embryos was determined. DESIGN AND METHODS Pre...

Background: Chromosome abnormalities are associated with poor morphology and development in human preimplantation embryos, all together lead to poor outcomes. This study aimed to explore altered expression of DNA damage pathways in “poor morphological and development embryos with sever aneuploidies”. Materials and Methods: Surplus day-4 embryos of PGD cases were pooled in two groups: Poor progn...

BACKGROUND In preimplantation mammalian development the transcription factor Sox2 (SRY-related HMG-box gene 2) forms a complex with Oct4 and functions in maintenance of self-renewal of the pluripotent inner cell mass (ICM). Previously it was shown that Sox2-/- embryos die soon after implantation. However, maternal Sox2 transcripts may mask an earlier phenotype. We investigated whether Sox2 is i...

Undifferentiated mouse embryonal carcinoma (EC) cells are capable of transactivating the adenovirus EIIa promoter in the absence of its normal transactivator, E1A protein, suggesting that EC cells contain an E1A-like activity. In an effort to identify where this activity appears during normal mouse development, mouse oocytes and preimplantation embryos were injected with plasmids containing the...

Provision of the maternal factors, albumin and/or insulin to embryos in vitro restores preimplantation morphological development and cell proliferation to that seen in vivo. The hypothesis that the preimplantation effects of insulin or albumin would be reflected in increased fetal growth rate was examined. Two-cell embryos were cultured 48-50 h in medium supplemented with 0.17 micromol/l, 15 mi...

Mammalian X-linked gene expression is highly regulated as female cells contain two and male one X chromosome (X). To adjust the X gene dosage between genders, female mouse preimplantation embryos undergo an imprinted form of X chromosome inactivation (iXCI) that requires both Rlim (also known as Rnf12) and the long non-coding RNA Xist. Moreover, it is thought that gene expression from the singl...

BACKGROUND An alteration in the mechanism that maintains the monoallelic, imprinted expression of genes can result in their biallelic expression and lead to disruptions in fetal development. Here, we examined the consequences of a loss of maintenance methylation at one specific stage of preimplantation, induced by a deficiency of the oocyte-derived Dnmt1o protein and known to produce biallelic ...

Stress coping mechanisms are critical to minimize or overcome damage caused by ever changing environmental conditions. They are designed to promote cell survival. The unfolded protein response (UPR) pathway is mobilized in response to the accumulation of unfolded proteins, ultimately in order to regain endoplasmic reticulum (ER) homeostasis. Various elements of coping responses to ER stress inc...

BACKGROUND The magnitude of the inner mitochondrial membrane potential (deltapsim) appears to influence the level of certain mitochondrial activities including regulation of ionic fluxes and ATP liberation, activities that are often compartmentalized or location dependent in cells. Recent evidence suggests that within cells, mitochondria can be heterogeneous with respect to deltapsim, and that ...

Serotonin receptors have been found in several reproductive organs as well as in the central nervous system. Serotonin-binding sites have been demonstrated in duck ovarian follicles and the testis, hamster ovaries, human granulosa cells and mouse placenta. Local production of serotonin by the rat ovary, oviduct, uterus and testis has also been reported. We analyzed the expression of three types...