Recent evidence that a syntaxin is required for cytokinesis in Caenorhabditis elegans embryos suggests that the mechanism of cell division in plant and animal cells may be more similar than previously imagined.

Background: For several years, mammalian cloning by splitting an early embryo or nuclear transfer into oocytes method has been successfully performed. Cloning is now also possible using adult somatic cells. Although it has now been 15 years since the first cloned mammals were generated from somatic cells using nuclear transfer (NT), the success rate for producing live offspring by cloning is lo...

The study of large animal embryonic stem cells (ESCs) in vitro has implications for the understanding of lineage differentiation and transgenesis. The first step for ESC derivation is the attachment of the embryo to a substrate on which they can form outgrowths. However, the culture conditions for large animal embryo attachment and ESC derivation have not been studied extensively. Defining cult...

We have examined the expression and function of the heterotrimeric GTP-binding protein Gq during early Xenopus embryogenesis. Abundant XGalphaq transcripts were detected in oocytes and early embryos by Northern blot analysis. In situ hybridization revealed that these transcripts are confined to the animal hemisphere of the mature oocyte and to the presumptive ectoderm of cleaving embryos. Micro...

OBJECTIVE To investigate lipopolysaccharide (LPS)-induced DNA damage in preimplanting embryonic and uterine cells during preimplantation period of pregnancy that may ultimately inhibit the process of implantation in mouse. DESIGN Animal study. SETTING Academic research environment. ANIMAL(S) Sixty four Park strain female mice. INTERVENTION(S) The "minimum dose" (MD) of LPS was injected ...

Synthesis of nuclear and cytoplasmic proteins was studied biochemically and autoradiographically in early loach (Misgurnus fossilis) and sea-urchin (Strongylocentrotus nudus) embryos. After incubation with [C]amino acids for 5-120 min the ratio of the specific activities of nuclear, mitochondrial and 12000g supernatant proteins was shown to be equal approximately to 6:1:2 in loach embryos and t...

Localization of nuclear beta-catenin initiates specification of vegetal fates in sea urchin embryos. We have identified SpKrl, a gene that is activated upon nuclear entry of beta-catenin. SpKrl is upregulated when nuclear beta-catenin activity is increased with LiCl and downregulated in embryos injected with molecules that inhibit beta-catenin nuclear function. LiCl-mediated SpKrl activation is...

It is well known that oocytes can reprogram differentiated cells, allowing animal cloning by nuclear transfer. We have recently shown that fertilized zygotes retain reprogramming activities, suggesting that such activities might also persist in cleavage-stage embryos. Here, we used chromosome transplantation techniques to investigate whether the blastomeres of two-cell-stage mouse embryos can r...

The zebrafish is an ideal organism for small molecule studies. The ability to use the whole organism allows complex in vivo phenotypes to be assayed and combines animal testing with screening. Embryos are easily treatable by waterborne exposure. The small size and abundance of embryos make zebrafish suitable for screening in a high-throughput manner in 96- or 48-well plates. Zebrafish embryos h...