Posttranscriptional maturation of the 3' end of eukaryotic pre-mRNAs occurs as a three-step pathway involving site-specific cleavage, polymerization of a poly(A) tail, and trimming of the newly synthesized tail to its mature length. While most of the factors essential for catalyzing these reactions have been identified, those that regulate them remain to be characterized. Previously, we demonst...

The number of studies in cell biology in which quantitative models accompany experiments has been growing steadily. Roughly, mathematical and computational techniques of these models can be classified as "differential equation based" (DE) or "agent based" (AB). Recently AB models have started to outnumber DE models, but understanding of AB philosophy and methodology is much less widespread than...

the development of culture media able to mimic the preovulatory stage of follicular environment and support nuclear and cytoplasmic maturation of oocyte is important for in-vitro fertilization (ivf) programs. it seems that the best culture media for embryonic development and cell cleavage is the natural composition which surrounds the oocyte which has been used occasionally in human ivf program...

abstract background: research studies on reproductive mechanism of laboratory animals are essential for further advancement of assisted reproductive techniques (art). one of these studies includes the assessment of in-vitro development of pre-implantation embryos. the objective was to compare the cleavage rates and morphology of in-vivo formed 2 to 8 cell embryos and blastocysts with in-vitro c...

Objective: Berberis vulgaris contains antioxidants that can inhibit DNA cleavage. The purpose of this study was to evaluate the antioxidant and protective activity of B. vulgaris on DNA cleavage. <span style="font-size: medium;"...

background: hla-g is a major histocompatibility complex (mhc), class ib molecule that is selectively expressed at the fetal–maternal interface. it is thought to play a role in protecting the fetus from the maternal immune response. interestingly, the preimplantation embryo development (ped) gene product qa-2 is also a mouse mhc class ib protein that affects cleavage and division of preimplantat...

background: the values of embryonic stem cell and cloning are evident. production of clone from embryonic stem cells can be achieved by introduction of stem cell into a tetraploid blastocyst. tetraploid blastocyst can be produced in vitro by electrofusion of 2-cell embryos. objective: the aim of this study was to assess the effect of different voltages and durations on fusion rate of bovine 2-c...

celecoxib, a specific cyclooxygenase-2 (cox-2) inhibitor, has been shown to possess antitumor activity in a variety of cancer cells. however, the antitumor activity of two synthesized cox-2 inhibitor derivatives ( a and b ) on human myeloid leukemia (k562) and breast adenocarcinoma (mcf-7) cancer cells has not been well established. this study was designed to investigate the morphological chang...

ring cleavage occurred when 1,2,4-triazino-1,2,4-triazines (3), (4) and (5) were treated with concentrated hydrochloric acid to yield n-substituted triazines (7) and (8). these confirm the given configuration assigned to the isomeric triazinotriazines. 6-methyl-2-phenyl-7h-oxazolo [3,2-b][1,2,4]-triazin-7-one (9) underwent ring cleavage on treatment with sodium alkoxide to afford 3-alkoxy-1,2,4...