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Results 251 - 300 of 2134
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Sano Chiaki - - 2009
Embryonic stem (ES) cells are characterized by pluripotency, in particular the ability to form a germline on injection into blastocysts. Despite numerous attempts, ES cell lines derived from rat embryos have not yet been established. The reason for this is unclear, although certain intrinsic biological differences among species and/or strains ...
Miki H - - 2009
Somatic cell cloning by nuclear transfer (NT) in mice is associated with hyperplastic placentas at term. To dissect the effects of embryonic and extraembryonic tissues on this clone-associated phenotype, we constructed diploid (2n) fused with (<-->) tetraploid (4n) chimeras from NT- and fertilization-derived (FD) embryos. Generally, the 4n cells contributed ...
Ogawa H - - 2009
Neither parthenogenetic (PG) nor androgenetic (AG) mouse embryos survive after day 9.5 of pregnancy, owing to the inadequate growth of extraembryonic tissues, including the placenta. At day 9.5 of pregnancy, the placental structures are poorly developed in PG embryos, while trophoblast giant cells are abundant at the implantation site in ...
Wenhui Wang, Darren Hewett, ...
This paper presents image processing algorithms recognising cell structures for an automated cell injection system. For suspended zebrafish embryos, the convex hull and convexity defects of the cytoplasm contour are used. For adherent endothelial cells, the surface and shadow information of the nucleoli is used. Overall, 550 zebrafish embryos were ...
Scheenen W J J M - - 2009
Transgenic animals are commonly employed to explore the function of individual proteins. Transgenic animal models include the mouse, the zebrafish, and the South African clawed toad Xenopus laevis. In contrast to mice and zebrafish, with Xenopus transgenesis DNA integration is mostly achieved in the one-cell stage. Moreover, Xenopus (as well ...
Weisblat David A - - 2009
One advantage of using Helobdella (leech) embryos as an experimental system is their amenability for microinjection. Blastomeres ranging in size from the zygote (400 microm diameter) down to micromeres and primary blast cells (approximately 20 microm diameter) can be injected by pressure under a dissecting microscope. Smaller cells can be ...
Yuri Shunsuke - - 2009
Sall4 is a mouse homolog of a causative gene of the autosomal dominant disorder Okihiro syndrome. We previously showed that the absence of Sall4 leads to lethality during peri-implantation and that Sall4-null embryonic stem (ES) cells proliferate poorly with intact pluripotency when cultured on feeder cells. Here, we report that, ...
Ketting René F - - 2009
MicroRNAs are known to play important roles in many different processes. However, their roles in shaping the early steps in embryogenesis have remained largely hidden. In this issue of Developmental Cell, Rosa et al. show that the miR-430/427/302 family of microRNAs has a distinct effect on Nodal signaling, affecting mesendoderm ...
Li Chao - - 2009
Mammalian parthenogenetic embryos (pE) are not viable due to placental deficiency, presumably resulting from lack of paternally expressed imprinted genes. Pluripotent parthenogenetic embryonic stem (pES) cells derived from pE could advance regenerative medicine by avoiding immuno-rejection and ethical roadblocks. We attempted to explore the epigenetic status of imprinted genes in ...
Kiessling Ann A - - 2009
To understand the molecular pathways that control early human embryo development. Improved methods of linear amplification of mRNAs and whole human genome microarray analyses were utilized to characterize gene expression in normal appearing 8-Cell human embryos, in comparison with published microarrays of human fibroblasts and pluripotent stem cells. Many genes ...
M??o Simone Cristina - - 2009
Ooplasmic factors drive nuclear organization after fertilization and are also important for re-programming in nuclear transfer procedures, in which artificial activation is essential for reconstructed embryos to progress in development. The present research evaluated the effect of pronuclear transfer (PT) between zygotes parthenogenetically activated with ionomycin followed by strontium (S) ...
Fan Yong - - 2009
The generation of patient-specific nuclear transfer embryonic stem cells holds huge promise in modern regenerative medicine and cell-based drug discovery. Since human in vivo matured oocytes are not readily available, human therapeutic cloning is developing slowly. Here, we investigated for the first time whether human polyspermic zygotes could support preimplantation ...
Nagy Nándor - - 2009
Bursa of Fabricius is a primary lymphoid organ in the birds and its microenvironment is responsible for the B cell maturation. The epithelial anlage develops through epithelial-mesenchymal interaction into which -as a third party - hemopoietic cells immigrate. Chemical bursectomy can be made by dipping or injecting eggs by testosterone ...
Furuya Hidetaka - - 2009
A new species of dicyemid mesozoan is described from Opisthoteuthis depressa Iijima and Ikeda, 1895, collected from Suruga Bay in Japan. Dicyemennea umbraculum n. sp. is a medium species that reaches about 3,500 mum in length. This species attaches to the surface of the renal appendages. The vermiform stages are ...
Wang Kai - - 2009
Interspecies somatic cell nuclear transfer (iSCNT) has the potential to become a useful tool to address basic questions about the nucleus-cytoplasm interactions between species. It has also been proposed as an alternative for the preservation of endangered species and to derive autologous embryonic stem cells. Using chimpanzee/ bovine iSCNT as ...
Nishioka Noriyuki - - 2009
Outside cells of the preimplantation mouse embryo form the trophectoderm (TE), a process requiring the transcription factor Tead4. Here, we show that transcriptionally active Tead4 can induce Cdx2 and other trophoblast genes in parallel in embryonic stem cells. In embryos, the Tead4 coactivator protein Yap localizes to nuclei of outside ...
Li Jianyuan - - 2009
Somatic cell nuclear transfer (SCNT) was used to generate patient-specific embryonic stem cells (ESCs) from blastocysts cloned by nuclear transfer (ntESCs). In this study, a total of 135 oocytes were obtained from 12 healthy donors (30-35 years). Human oocytes, obtained within 2 h following transvaginal aspiration, were enucleated using a ...
Larina Irina V IV Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, - - 2009
The development of the cardiovascular system is a highly dynamic process dependent on multiple signaling pathways regulating proliferation, differentiation, migration, cell-cell and cell-matrix interactions. To characterize cell and tissue dynamics during the formation of the cardiovascular system in mice, we generated a novel transgenic mouse line, Tg(Flk1::myr-mCherry), in which endothelial ...
Siqueira da Fonseca S A - - 2009
OBJECTIVES: In this study, we aimed at determining whether human immature dental pulp stem cells (hIDPSC) would be able to contribute to different cell types in mouse blastocysts without damaging them. Also, we analysed whether these blastocysts would progress further into embryogenesis when implanted to the uterus of foster mice, ...
Lei Lei - - 2009
Polyploid mouse embryos are important models for understanding the mechanisms of cleavage and preimplantation development in mammals. In this study, hexaploid (6n) mouse embryos were produced by the electrofusion of blastomeres from diploid (2n) and tetraploid (4n) embryos at the 2-cell stage. Furthermore, the developmental pattern of hexaploid embryos was ...
Liu Hong-Bo - - 2009
Miniature pigs are valuable for research in xenotransplantation and as models for investigating human diseases. Although many mammalian species have been cloned, the success rates have been very low, especially in the pig. In the present study, an attempt was made to optimize somatic cell nuclear transfer (SCNT) protocols for ...
Fu J-J - - 2009
Embryo implantation involves invasion of placental extravillous trophoblast cell (EVTs) into the uterus. Hyperactive EVT invasion occurs in hydatidiform moles and choriocarcinomas. We have previously demonstrated that the 20S proteasome is involved in mouse embryo implantation and its action is mediated via regulating the expression and activities of matrix metalloproteinase ...
Horng Jiun-Lin - - 2009
It is important to maintain internal pH homeostasis in biological systems. In our previous studies, H(+)-ATPase-rich (HR) cells were found to be responsible for proton secretion in the skin of zebrafish embryos during development. In this study, zebrafish embryos were exposed to acidic and basic waters to investigate the regulation ...
Hao, Ru
The main aim of this thesis was to find out which donor cells would be most suitable for production of cloned rabbits with a targeted modification of their genome, and their corresponding patterns of reprogramming hetero- and euchromatic histone modifications (H3K4m2/3 and H3K27m3). For these purposes, we carried out NT ...
Naruse Kenji - - 2009
Streptolysin O (SLO) is a known bacterial protein that forms very large pores in the plasma membranes of mammalian cells. SLO has been used in the delivery of proteins into living cells following permeabilization. The objective of this study was to investigate the effects of SLO treatment in donor cells ...
Kwiatkowski Adam V - - 2009
A complex program of cell intrinsic and extrinsic signals guide cortical development. Although genetic studies in mice have uncovered roles for numerous genes and gene families in multiple aspects of corticogenesis, determining their cell autonomous functions is often complicated by pleiotropic defects. Here we describe a novel lentiviral-based method to ...
Zeng Xin-Xin I - - 2009
Phospholipase D (PLD) hydrolyzes phosphatidylcholine to generate phosphatidic acid and choline. Studies in cultured cells and Drosophila melanogaster have implicated PLD in the regulation of many cellular functions, including intracellular vesicle trafficking, cell proliferation and differentiation. However, the function of PLD in vertebrate development has not been explored. Here we ...
Fujimori Toshihiko - - 2009
During the 4 days after fertilization, the mouse embryo proceeds in its development within the zona pellucida and reaches the blastocyst stage, when a newly formed embryonic-abembryonic (E-Ab) axis is settled before implantation. The previous findings suggested that the shape of the zona pellucida, which may function as an environmental ...
Gavrilov Svetlana - - 2009
Human embryonic stem cells (hESC) hold great promise for use in regenerative medicine. However, the extraordinary potential of hESC as therapeutic tools is tempered by ethical, moral and political issues surrounding their derivation from human embryos. It has previously been proposed that ethical criteria applied to essential organ donation could ...
Geach Timothy J TJ Division of Developmental Biology, National Institute for Medical Research, The Ridgeway, Mill Hill, London, UKNW7 - - 2009
Bio-electrosprays, a recently pioneered direct cell engineering approach, have been demonstrated to handle living cells including stem cells for the development of active specialized and unspecialized microenvironments. This electric field driven technique is currently undergoing vigorous development where the technique is racing towards possible clinical utility. Although this direct cell ...
Arnold Sebastian J - - 2009
Genetic studies have identified the key signalling pathways and developmentally regulated transcription factors that govern cell lineage allocation and axis patterning in the early mammalian embryo. Recent advances have uncovered details of the molecular circuits that tightly control cell growth and differentiation in the mammalian embryo from the blastocyst stage, ...
Rehm E Jay - - 2009
The great diversity of arthropod body plans, together with our detailed understanding of fruit fly development, makes arthropods a premier taxon for examining the evolutionary diversification of developmental patterns and hence the diversity of extant life. Crustaceans, in particular, show a remarkable range of morphologies and provide a useful outgroup ...
Kemp Hilary A - - 2009
One of the most powerful tools used to gain insight into complex developmental processes is the analysis of chimeric embryos. A chimera is defined as an organism that contains cells from more than one animal; mosaics are one type of chimera in which cells from more than one genotype are ...
Maalouf Walid E - - 2009
BACKGROUND: Genome reprogramming in early mouse embryos is associated with nuclear reorganization and particular features such as the peculiar distribution of centromeric and pericentric heterochromatin during the first developmental stage. This zygote-specific heterochromatin organization could be observed both in maternal and paternal pronuclei after natural fertilization as well as in ...
- - 2009
Embryo of an annual fish (Austrolebias charrua) in the last dormancy stage, diapause III. The embryo, surrounded by a transparent vitelline envelope, is in the pre-hatching stage. A prominent eye and part of the pigmented body and tail are apparent. Why annual fishes? Annual fishes (Order Cyprinodontiformes) are a special ...
Goulding Morgan Q - - 2009
Cell lineage studies in mollusk embryos have documented numerous variations on the lophotrochozoan theme of spiral cleavage. In the experimentally tractable embryo of the mud snail Ilyanassa, cell lineage has previously been described only up to the 29-cell stage. Here I provide a chronology of cell divisions in Ilyanassa to ...
Mitalipov Shoukhrat - - 2009
Mammalian development commences with the totipotent zygote which is capable of developing into all the specialized cells that make up the adult animal. As development unfolds, cells of the early embryo proliferate and differentiate into the first two lineages, the pluripotent inner cell mass and the trophectoderm. Pluripotent cells can ...
Plück Anne - - 2009
Since the technique of introducing a targeted mutation ('gene targeting') into the mouse genome was published almost 20 years ago (Cell 51:503-512, 1987), the number of mouse mutants (mouse models) is increasing, especially after the advent of the full mouse genomic sequence in 2002 and the human genomic sequences in ...
Winkler Johannes - - 2009
The derivation of pluripotent embryonic stem (ES) cell lines has opened up new areas of research in basic and applied science, most significantly in developmental biology and regenerative medicine. While application-oriented research has for the most part focussed on obtaining differentiated, organotypic cells from ES cells for future cell grafting ...
Sliwinska Elwira - - 2009
The completion of germination of seeds of Arabidopsis thaliana is marked by the appearance of the radicle through the surrounding endosperm and testa. Using confocal microscopy and green fluorescent protein (GFP)-transformed embryos to highlight the epidermal cell walls it has been possible to conduct time-lapse photography of individual embryos during ...
Díez-Torre Alejandro - - 2009
In recent years, the reversion of the cancer phenotype of human melanoma cells in developing zebrafish and chick embryos has been reported. The aim of this review is to revise these and other related contributions regarding the regulation of embryonic cancer and to provide a framework with which to understand ...
Sasikumar Satish - - 2009
Intracellular membrane trafficking regulates a wide variety of developmental processes, including cell and tissue morphogenesis. Here we report developmental expression of Drosophila Rab11, a small GTP-binding protein, required for both endocytic recycling and exocytosis. Rab11 is expressed in the epithelial cell types of diverse lineages at all developmental stages, beginning ...
Shipley Rebecca J - - 2009
A theoretical exploration of cell distribution on the mouse blastocyst is conducted. A model ball of cells represents the morula which develops into a 32-cell model blastocyst that is enclosed in a spherical surface with a hemispherical cavity at one end. In the combinatorial analysis it is assumed that each ...
Plück Anne - - 2009
This chapter describes the tools and the experimental route of targeted manipulation by aggregation in the mouse using targeted embryonic stem cells (ES cells). Instead of injecting ES cells into the blastocoel of a diploid blastocyst-stage embryo (3.5 dpc) ES cells can be brought together with diploid morula-stage embryos (2.5 ...
Lahl Vera - - 2009
In order to evaluate the evolutionary preservation of developmental programs during nematode embryogenesis, we searched for close relatives of the model system Caenorhabditis elegans with deviant patterns. The parthenogenetically reproducing species Diploscapter coronatus shows prominent differences to C. elegans. While in the 2-cell stage of C. elegans a rotation of ...
Wu Dongmei - - 2009
In 2006, Yamanaka and colleagues first demonstrated that retrovirus-mediated delivery and expression of Oct4, Sox2, c-Myc and Klf4 is capable of inducing the pluripotent state in mouse fibroblasts.(1) The same group also reported the successful reprogramming of human somatic cells into induced pluripotent stem (iPS) cells using human versions of ...
Dard Nicolas - - 2009
Asymmetric cell divisions are involved in the divergence of the first two lineages of the pre-implantation mouse embryo. They first take place after cell polarization (during compaction) at the 8-cell stage. It is thought that, in contrast to many species, spindle orientation is random, although there is no direct evidence ...
Dard Nicolas - - 2009
During mammalian preimplantation development, lineage divergence seems to be controlled by the interplay between asymmetric cell division (once cells are polarized) and positional information. In the mouse embryo, two distinct cell populations are first observed at the 16-cell stage and can be distinguished by both their position (outside or inside) ...
Debeb Bisrat G - - 2009
The extraembryonic endoderm (ExEn) defines the yolk sac, a set of membranes that provide essential support for mammalian embryos. Recent findings suggest that the committed ExEn precursor is present already in the embryonic Inner Cell Mass (ICM) as a group of cells that intermingles with the closely related epiblast precursor. ...
Bell Christine E - - 2009
SNAI1 and SNAI2 are transcription factors that initiate Epithelial-to-Mesenchymal cell transitions throughout development and in cancer metastasis. Here we show novel expression of SNAI1 and SNAI2 throughout mouse preimplantation development revealing asymmetrical localization of both SNAI1 and SNAI2 in individual blastomeres beginning at the 2-cell stage through to the 8-cell ...
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