Anna Katerina Hadjantonakis

..The approach we describe can be used to document morphogenetic cell and tissue rearrangements in living embryos and paves the way for a live digitized anatomical atlas of Ciona...

..Lig3-null cells are not sensitive to several DNA-damaging agents that sensitize Xrcc1-deficient cells. Our results establish a role for Lig3 in mitochondria, but distinguish it from its interacting protein Xrcc1...

..This tiny structure has now been observed to express nearly 600 genes in a sex-specific fashion, including at least one gene (Rhox/Pem) expressed only in females from their paternal X chromosome...

..A report on the Mouse Molecular Genetics meeting, Hinxton, UK, 5-9 September 2007...

..As a result, imaging using autofluorescent protein reporters is gaining popularity in mouse transgenic and targeted mutagenesis applications...

..However, analysis of implantation-delayed blastocysts, revealed a role for SOX17 in the maintenance of PrE epithelial integrity, with the absence of SOX17 leading to premature delamination and migration of parietal endoderm...

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..Taken together, our data suggest that XEN cells can be differentiated towards an exVE identity upon BMP4 stimulation and therefore represent a valuable tool for investigating PrE lineage differentiation...

..These features establish the Tg(Eomes::GFP) BAC transgenic strain as a novel reagent for both live imaging and the isolation of Eomes expressing cells from specific locations within the embryo...

..A mutagenesis approach directing the stepwise evolution of DsRed has produced mRFP1, the first true monomer. mRFP1 currently represents an attractive autofluorescent reporter for use in heterologous systems...

..These mice represent a valuable resource for live imaging as well as identification, quantitation, and isolation of cells from the primitive and definitive endoderm lineages of the developing mouse embryo...

..Taken together, our data suggest a role for PDGF signaling in the expansion of the ExEn lineage. Our observations also uncover a possible role for the PrE in regulating the size of the pluripotent EPI compartment...

..This is the first transcriptome assembled for a single hematopoietic lineage of the embryo over the course of its differentiation...

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..The Afp::mCherry reporter was also noted to be expressed in other documented sites of Afp expression including hepatocytes as well as in pancreas, digestive tract, and brain of postnatal mice...

..This strain should be extremely useful for studies of cell behavior during ureteric bud branching morphogenesis in wild type and mutant mouse lines...

..Subsequently, a gradual progression towards a mutually exclusive expression of PrE- and EPI-specific markers occurs. Finally, cell sorting is achieved by a variety of cell behaviours and by selective apoptosis...

..In this review, we will discuss how the isolation and genetic manipulation of murine stem cells representing each of these three lineages has contributed to our understanding of the molecular basis of early developmental events...

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..In addition, pathway analysis suggests that the ExEn may mediate some of its functions through a non-classical MAP Kinase signaling pathway downstream of TAK1...

..In situ visualization of these processes in living specimens is a major goal, as it provides unprecedented detail of the individual cellular behaviors, which translate into the large-scale tissue rearrangements that shape the embryo...

..Here, we review recent advances in the application of FPs for live imaging in the early mouse embryo, as well as some of the methods used for ex utero embryo development that facilitate on-stage time-lapse specimen visualization...

..Photomodulatable fluorescent proteins are one of the emerging classes of genetically-encoded fluorescent proteins...

..Our protocols provide a simple and efficient strategy to utilize the whole GENSAT BAC library to create hundreds of novel fluorescent cell lines for use in ES cell biology...

..Live imaging using genetically encoded fluorescent protein reporters is pushing the envelope of our understanding by uncovering unprecedented insights into mouse development and leading to the formulation of quantitative accurate models...

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..A recent report offers the first 'proof of principle' of such cloning for therapeutic purposes, referred to as nuclear transplantation to produce stem cells for autologous transplantation...

..However, even though several transgenic Wnt/β-catenin reporter strains have been generated, to date, none provides the single-cell resolution favored for live imaging studies...

..Investigating the cell behaviors underlying the morphogenesis of muscle in ascidians may therefore reveal the evolutionarily conserved mechanisms operating during this process...

..Instead, depending on concentration, we noted no effect or conversion of all ICM cells to GATA6-positive PrE. We propose that heterogeneities in the availability of FGF produce the salt-and-pepper distribution of lineage-biased cells...

..Here we describe a novel role for the T-box transcription factor gene Tbx6 in left/right body axis determination in the mouse...

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..The recent development of protocols to isolate eXtraembryonic ENdoderm (XEN) stem cells, representing the extraembryonic endoderm lineage, from blastocyst stage mouse embryos offers new tools for the genetic dissection of cardiogenesis...

..Here, we review some recent advances in this rapidly evolving field as applied to live-imaging capabilities in the mouse, the most genetically tractable mammalian model organism for embryologists...

..The Ttr::Cre strain can therefore be used as a tool for genetic modifications within the visceral endoderm lineage...

..The cell behaviors and molecular mechanisms promoting transitions between these two states in the early mouse embryo are discussed in this review...

..This chapter describes a simple and economical technique used to generate mouse chimeras by embryo aggregation. Multiple aggregation combinations are described each of which can be tailored to answer particular biological questions...

..Variability in nuclear appearance and undersampled volumetric data make this a challenge...

..Red and green fluorescent reporter-expressing cells are located in the endoderm layer along villi, but excluded from the crypt stem cell zone. See the article by Viotti at al. in this issue...

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..We discuss recent advances that have focused on elucidating how the salt-and-pepper pattern is established and then resolved within the ICM, leading to the correct apposition of cell lineages in preparation for implantation...

..3D reconstructions of confocal z-stacks reveal reporter localization throughout the visceral endoderm (righthand image of each pair). See the paper by Kwon and Hadjantonakis in this issue...

..Importantly, these technologies allow direct visual access to complex events as they happen in their native environment, which provides greater insights into mammalian biology than ever before...

..We have previously demonstrated the utility and developmental neutrality of enhanced green fluorescent protein (EGFP) in embryonic stem (ES) cells and mice 2...

..These transgenic lines permit real-time imaging in normal and pathological vasculogenesis and angiogenesis to track individual cells and mitotic events at a level of detail that is unprecedented in the mouse...

..Together, these findings identify Tbr2 as a critical factor for the specification of IPCs during corticogenesis...

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..Furthermore, combining these reporters with the study of mouse mutants will be a step forward in understanding the inter- and intracellular behaviors underlying morphogenesis in both normal and mutant contexts...

..Thus, the first cleavage contributes to breaking the symmetry of the embryo, generating blastomeres with different developmental characteristics...

..These findings suggest that the results of previously published tetraploid complementation assays may be influenced by the presence of tetraploid cells in the otherwise diploid embryonic regions...

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