The aim of this study was to examine the possible morphological and morphometric changes resulting from vitrification of embryos at the cleavage stage. In this study, 30 mice early-cleavage embryos at different stages of cleavage, resulting from in vitro fertilization (IVF) techniques, were examined before and after vitrification. Digital images were taken from embryos before and after vitrific...

Cleavage is one of the initial steps of embryogenesis, and is characterized by a series of symmetric and synchronous cell divisions. We showed that p38 MAP kinase (p38) is asymmetrically activated on one side of the blastodisc during the early cleavage period in zebrafish (Danio rerio) embryos. When a dominant negative (DN) form of p38 was uniformly expressed, blastomere cleavage was impaired o...

Some embryos of Ciona intestinalis which were permanently cleavage-arrested with cytochalasin B at the 1-cell, 4-cell, or 8-cell stages produced, after 12 or 16 h of development time (18 degrees C), a level of muscle acetylcholinesterase activity equal to that found in normal early and later larval stage embryos of the same age. Enzyme activity was measured quantitatively in single whole embryo...

Chromosomal translocations involving the MLL gene occur in about 80% of infant leukemia. In the search for possible agents inducing infant leukemia, we identified bioflavonoids, natural substances in food as well as in dietary supplements, that cause site-specific DNA cleavage in the MLL breakpoint cluster region (BCR) in vivo. The MLL BCR DNA cleavage was shown in primary progenitor hematopoie...

The Beclin-1 protein is essential for the initiation of autophagy, and recent studies suggest this function may be compromised in Alzheimer's disease (AD). In addition, in vitro studies have supported a loss of function of Beclin-1 due to proteolytic modification by caspases. In the present study, we examined whether caspase-cleavage of Beclin-1 occurs in the AD brain by designing a site-direct...

Mouse eggs were activated by treatment with hyaluronidase which removed the follicle cell9, followed by culture in vitro, and examined at the first cleavage mitosis. Second polar body extrusion usually occurred and haploid parthenogenesis was initiated. Air-dried chromosome preparations were made between 11 and 15-5 h after activation. Out of the 308 eggs examined 74 had already progressed to t...

Cleavage is one of the initial steps of embryogenesis, and is characterized by a series of symmetric and synchronous cell divisions. We showed that p38 MAP kinase (p38) is asymmetrically activated on one side of the blastodisc during the early cleavage period in zebrafish ( Danio rerio ) embryos. When a dominant negative (DN) form of p38 was uniformly expressed, blastomere cleavage was impaired...

The chordates include vertebrates plus two groups of invertebrates (the cephalochordates and tunicates). Previous embryonic fate maps of the cephalochordate amphioxus (Branchiostoma) were influenced by preconceptions that early development in amphioxus and ascidian tunicates should be fundamentally the same and that the early amphioxus embryo, like that of amphibians, should have ventral mesode...

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...