Recent studies showed that small interfering RNAs (siRNAs) and Piwi-interacting RNA (piRNA) in mammalian germ cells play important roles in retrotransposon silencing and gametogenesis. However, subsequent contribution of those small RNAs to early mammalian development remains poorly understood. We investigated the expression profiles of small RNAs in mouse metaphase II oocytes, 8-16-cell stage ...

background: oocyte maturation and subsequent in vitro production (ivp) of embryos are affected by diverse groups of chemicals in maturation medium which are needed for successful mammalian oocyte maturation during which the dramatic cytoplasmic and nuclear reprogramming events take place. this study was designed to evaluate the effects of protein source (fetal bovine serum, fbs, and bovine seru...

Oct4 is a mammalian POU transcription factor expressed by early embryo cells and germ cells. We report that the activity of Oct4 is essential for the identity of the pluripotential founder cell population in the mammalian embryo. Oct4-deficient embryos develop to the blastocyst stage, but the inner cell mass cells are not pluripotent. Instead, they are restricted to differentiation along the ex...

Embryo implantation is a critical step in mammalian reproduction and includes apposition of the blastocyst, attachment to the uterine epithelium and decidualization of the uterine stroma. However, the key mechanism underlying embryo implantation remains to be elucidated. In recent years, high-throughput transcriptomic and proteomic approaches make it possible for studying the expression levels ...

Loss of Max function in the mouse resulted in generalized developmental arrest of both embryonic and extraembryonic tissues at early postimplantation (approximately E5.5-6.5), coincident with loss or dilution of maternal Max stores in the expanding embryo in vivo and in blastocyst outgrowths in vitro. Developmentally arrested embryos were reduced in size and exhibited widespread cytological deg...

twik2 ion channels (k2p6.1, encoded by a gene named kcnk6) belong to the family of two-pore domain potassium channels. twik2 is also considered as a “silent” channel because of its inability to produce measurable currents in heterologous expression systems and its intracellular retention. it is expressed in different mammalian tissues including lymphoid organs and the vascular system. however, ...

The overall DNA methylation level sharply decreases from the zygote to the blastocyst stage despite the presence of high levels of DNA methyltransferase (Dnmt1). Surprisingly, the enzyme is localized in the cytoplasm of early embryos despite the presence of several functional nuclear localization signals. We mapped a region in the NH(2)-terminal, regulatory domain of Dnmt1 that is necessary and...

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)...