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  • Cell & Developmental Biology  (90)
  • 1990-1994  (90)
  • 1
    Electronic Resource
    Electronic Resource
    Nuclear transfer and electrofusion in bovine in vitro-matured/in vitro-fertilized embryos: Effect of media and electrical fusion parameters (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 36 (1993), S. 307-312 
    Details
    ISSN: 1040-452X
    Keywords: Micromanipulation ; IVM oocytes ; IVM/IVF donor embryos ; Cytochalasin B ; Nocodazole ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In this study, micromanipulation and electrofusion conditions for the cloning of in vitro-produced bovine embryos (here after termed IVM/IVF embryos) derived from in vitro-matured (IVM) and in vitro-fertilized (IVF) oocytes were established. The effect of DC field strength on the fusion rate was tested in a model system using pronuclear stage embryos in which a cytoplasmic vesicle was removed and reinserted. Efficient fusion (80%) was obtained by applying a pulse of 1.75 kV/cm for 40 μsec. In vitro development of manipulated pronuclear stage embryos was as efficient as that of unmanipulated control embryos. Different fusion media were compared in the cloning procedure, using IVM oocytes as recipients and blastomeres from day 6 IVM/IVF donor embryos. Zimmermann cell fusion medium reduced the lysis of nuclear transfer embryos compared to F300 (5% vs. 25%). The effects of drugs disrupting the microfilaments and microtubuli were determined. Neither the addition of cytochalasin B (CCB) for 1 hr in the postfusion medium nor incubation of donor blastomeres with nocodazole had a significant effect on the fusion or cleavage rate of the nuclear transfer embryos. Additional experiments demonstrated that there was no difference in developmental potential between nuclear transfer embryos allowed to develop in vitro or in vivo and that the embryos gave a 15% pregnancy rate in recipient cattle. © 1993 Wiley-Liss, Inc.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080360304
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  • 2
    Electronic Resource
    Electronic Resource
    Ultrastructural evidence for the axonal localization of caudodorsal cell hormone mRNA in the central nervous system of the mollusc Lymnaea stagnalis (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 25 (1993), S. 12-18 
    Details
    ISSN: 1059-910X
    Keywords: In situ hybridization ; Digoxigenin ; Electron microscopy ; Cryosections ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: The technique of in situ hybridization has been used to evaluate the expression of an ovulation hormone mRNA (caudodorsal cell hormone; CDCH) in the central nervous system (CNS) of the mollusc Lymnaea stagnalis. Hybridization with radioactive as well as with nonradioactive labeled oligonucleotide and plasmid probes revealed a specific labeling on cell bodies of caudodorsal cells (CDCs), which are known to produce CDCH, on the light microscopical level. In addition, specific labeling was observed outside the cell bodies, as far as the cerebral commissure, where CDCH is released in the haemolymph. To investigate whether these signals represent an axonal localization of the CDCH mRNA, we performed in situ hybridization at the electron microscopical (EM) level. The results showed an intraaxonal localization of CDCH mRNA with digoxigenin labeled oligonucleotide and plasmid probes. Gold labeling was observed in secretion granules, and double labeling experiments showed that these granules also contain CDCH. This specific intragranular localization suggest that CDCH mRNA is transported through the axon and released by exocytosis in the haemolymph. © 1993 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070250104
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  • 3
    Electronic Resource
    Electronic Resource
    Comparative microanatomy of the branchial sieve in three sympatric cyprinid species, related to filter-feeding mechanisms (1994)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 219 (1994), S. 73-87 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: According to the reducible-channel model of filter-feeding (Hoogenboezem et al., '91), small food particles are retained in the channels between the medial gill rakers, while the mesh size can be reduced by lowering the lateral gill rakers into these channels. This movement requires that all lateral gill rakers have a m. abductor branchiospinalis (MAB). MAB runs from the radii branchiales to the raker feet. It is present on the lateral side of all four gill arches of the cyprinids Abramis brama and Cyprinus carpio but only on the first arch of Blicca bjoerkna, Rutilus rutilus, Ctenopharyngodon idella, Aspius aspius, and Scardinius erythrophthalmus. Therefore, the latter species do not fulfill the structural requirement for the reducible-channel model, whereas A. brama and C. carpio do. Laboratory and field data confirm that A. brama and C. carpio can reduce their mesh size according to this model and are the better filter-feeders. The seven cyprinid species studied show the same principal microanatomy of their branchial sieve. M. abductor filamenti is a sheet of muscle fibers between the lateral radii branchiales and the ceratobranchial bone. M. branchialis superficialis is a specialized region of the subepithelial muscle fiber network, with origins along both sides of the ceratobranchial bone. The lateral gill rakers of the first gill arch differ conspicuously from all other rakers. They are longer and flattened, and they are tilted anteriorly. They probably form a sieve across the wide slit between the first gill arch and the operculum. The most revealing anatomical feature is the presence of MABs on gill arches 1-4. It might be a suitable bio-assay for identifying the better facultative filter-feeders among cyprinids. © 1994 Wiley-Liss, Inc.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052190109
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  • 4
    Electronic Resource
    Electronic Resource
    Protein-DNA interactions at the H4-Site III upstream transcriptional element of a cell cycle regulated histone H4 gene: Differences in normal versus tumor cells (1992)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 49 (1992), S. 93-110 
    Details
    ISSN: 0730-2312
    Keywords: DNA-binding proteins ; Differentiation ; Distal promoter elements ; Proliferation ; Cell growth ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Upstream sequences of the H4 histone gene FO108 located between nt -418 to -213 are stimulatory for in vivo transcription. This domain contains one protein/DNA interaction site (H4-Site III) that binds factor H4UA-1. Based on methylation interference, copper-phenanthroline protection, and competition assays, we show that H4UA-1 interacts with sequences between nt -345 to -332 containing an element displaying sequence-similarity with the thyroid hormone response element (TRE). Using gel retardation assays, we also demonstrate that H4UA-1 binding activity is abolished at low concentrations of Zn2+ (0.75 mM), a characteristic shared with the thyroid hormone (TH) receptor DNA binding protein. Interestingly, phosphatase-treatment of nuclear proteins inhibits formation of the H4UA-1 protein/DNA complex, although a complex with higher mobility (H4UA-1b) can be detected; both complexes share identical protein-DNA contacts and competition behaviors. These findings suggest that phosphorylation may be involved in the regulation of H4-Site III protein/DNA interactions by directly altering protein/protein associations. H4-Site III interactions were examined in several cell culture systems during cell growth and differentiation. We find that H4UA-1 binding activity is present during the cell cycle of both normal diploid and transformed cells. However, during differentiation of normal diploid rat calvarial osteoblasts, we observe a selective loss of the H4UA-1/H4-Site III interaction, concomitant with an increase of the H4UA-1b/H4-Site III complex, indicating modifications in the heteromeric nature of protein/DNA interactions during downregulation of transcription at the cessation of proliferation. Transformed cells have elevated levels of H4UA-1, whereas H4UA-1b is predominantly present in normal diploid cells; this alteration in the ratio of H4UA-1 and H4UA-1b binding activities may reflect deregulation of H4-Site III interactions in transformed cells. We propose that H4-Site III interactions may contribute, together with protein/DNA interactions at proximal regulatory sequences, in determining the level of H4-FO108 histone gene transcription.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240490115
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  • 5
    Electronic Resource
    Electronic Resource
    Cell cycle controlled histone H1, H3, and H4 genes share unusual arrangements of recognition motifs for HiNF-D supporting a coordinate promoter binding mechanism (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 159 (1994), S. 515-530 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cell cycle and growth control of the DNA binding and transactivation functions of regulatory factors provides a direct mechanism by which cells may coordinate transcription of a multitude of genes in proliferating cells. The promoters of human DNA replication dependent histone H4, H3, and H1 genes interact with at least seven distinct proteins. One of these proteins is a proliferation-specific nuclear factor, HiNF-D, that interacts with a key cis-regulatory element (H4-Site II; 41 bp) present in H4 genes. Here we describe binding sites for HiNF-D in the promoters of H3 and H1 genes using cross-competition, deletion analysis, and methylation interference assays, and we show that HiNF-D recognizes intricate arrangements of at least two sequence elements (CA- and AG-motifs). These recognition motifs are irregularly dispersed and distantly positioned in the proximal promoters (200 bp) of both the H3 and H1 genes. In all cases, these motifs either overlap or are in close proximity to other established transcriptional elements, including ATF and CCAAT sequences. Although HiNF-D can interact with low affinity to a core recognition domain, auxiliary elements in both the distal and proximal portions of each promoter cooperatively enhance HiNF-D binding. Thus, HiNF-D appears to bridge remote regulatory regions, which may juxtapose additional trans-activating proteins interacting within histone gene promoters. Consistent with observations in many cell culture systems, the interactions of HiNF-D with the H4, H3, and H1 promoters are modulated in parallel during the cessation of proliferation in both osteosarcoma cells and normal diploid osteoblasts, and these events occur in conjunction with concerted changes in histone gene expression. Thus, HiNF-D represents a candidate participant in coordinating transcriptional control of several histone gene classes. © 1994 wiley-Liss, Inc.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041590316
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  • 6
    Electronic Resource
    Electronic Resource
    Structural aspects of bovine oocyte maturation in vitro (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 208-214 
    Details
    ISSN: 1040-452X
    Keywords: Cumulus-oocyte complex ; COC ; Culture of oocytes ; Cow ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Bovine cumulus-oocyte complexes (COCS) were collected from 4-8 mm follicles and graded inot four categories on their morphological characteristics. These four categories were matured in vitro and processed for transmission electron microscopy at 24 h after the onset of culture. The morphology of the four groups of oocytes was analysed and compared with that of occytes that had matured in vivi and were collected 20-23 h after the preovulatory luteinizing hormone peak. After in vivo maturation, oocytes formed a homogeneous group with respect to their morphologicalo characteristics. After in vitro muturation, the oocytes formed a heterogeneous group with respect to their morphology between as well as within the four categories of oocytes. Oocytes from the first three categories showed the same morphology after in vitro maturation. The fourth category showed some specific characteristics: (1) vacuolization, (2) flattening of cumulus cells, and (3) almost complete lack of cortical granules in some category 4 oocytes. These characteristics are interpreted as signs of degeneration. Besides these aspects of degeneration, other deviations from normal development were seen: (1) retraction of cumulus cell process endings from the oocyte without the breaking down of these processes, (2) retardation of some aspects of the cytoplasmic maturation, and (3) incomplete cumulus expansion. It is concluded that oocytes capable of development in vitro show a large morphological variability before the onset of culture. In vitro maturation systems can support normal development, but many oocytes show signs of degeneration and deviant development after in vitro maturation.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080310308
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  • 7
    Electronic Resource
    Electronic Resource
    Stage-specific appearance of the mouse antigen TEC-3 in normal and nuclear transfer bovine embryos: Re-expression after nuclear transfer (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 37 (1994), S. 27-33 
    Details
    ISSN: 1040-452X
    Keywords: TEC-03 ; Bovine embryos ; Nuclear transfer ; Nuclear reprogramming ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Bovine embryos, recovered from the uterus in vivo or derived from in vitro matured and in vitro fertilized oocytes, were investigated for the presence of the developmentally regulated mouse antigen TEC-3 by indirect immunofluorescence. During preimplantation embryo development TEC-3 is expressed on bovine morulae and blastocysts. It is absent from unfertilized and fertilized oocytes, and from all stages before the 32-cell stage. The finding that TEC-3 is not expressed before the onset of embryonic transcription, which occurs at the eight-cell stage in the bovine, but only when the embryonic genome is active, makes it a potential marker for studying nuclear reprogramming after nuclear transfer. Nuclear transfer embryos were made by electrical fusion of blastomeres from morulae derived in vivo with enucleated metaphase II oocytes. Indirect immunofluorescence with the TEC-03 antibody showed that the TEC-3 antigen, present on blastomeres of the morula stage embryo, disappeared after fusion and was expressed again when the nuclear transfer embryos developed to the morula and blastocyst stage. These data suggest that the bovine embryonic nucleus may be able to revert to the equivalent of an earlier developmental stage when transferred to ooplasm, and is then capable of following the normal developmental program. © 1994 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080370105
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  • 8
    Electronic Resource
    Electronic Resource
    The study of partially ordered \documentclass{article}\pagestyle{empty}\begin{document}$ 1 \frac{1}{2} 0 $\end{document} alloys by HREM (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 25 (1993), S. 169-170 
    Details
    ISSN: 1059-910X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070250208
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  • 9
    Electronic Resource
    Electronic Resource
    Heterologous cell contacts and metabolic coupling in bovine cumulus oocyte complexes (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 28 (1991), S. 255-259 
    Details
    ISSN: 1040-452X
    Keywords: Cow ; Cattle ; Gap junctions ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The integrity of the cumulus cell processes were studied in four categories of bovine cumulus oocyte complexes (COCs) selected on their morphological characteristics. Three different types of cumulus cell process endings (CCPEs) were identified, one penetrating the cortex, another not penetrating the cortex, and a third form was intermediate and more rare in appearance. The process endings that penetrated the cortex frequently made gap junctions with the oolemma. The division of the three types of CCPEs over the four different COC categories was specific for three of the four categories. The first-category COC predominantly possessed the penetrating CCPE, the fourth-category COC possessed predominantly the nonpenetrating CCPE, and the second and third categories had both types of CCPEs. The metabolic coupling of the cumulus-oocyte contacts was assessed by means of incorporation of 3H-choline into the oocyte. The majority of category 4 COCs transferred low levels of choline into the oocyte while the majority of the oocytes of the other three categories transferred high levels of choline into the oocyte. Category 4 includes a smaller proportion of oocytes capable of cleaving after fertilization than the other three categories. This reduced developmental capacity is probably due to the loss of metabolic coupling before the onset of culture.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080280307
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  • 10
    Electronic Resource
    Electronic Resource
    Lysophosphatidic acid and bradykinin have opposite effects on phenotypic transformation of normal rat kidney cells (1994)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 480-489 
    Details
    ISSN: 0730-2312
    Keywords: contact-inhibition ; prostaglandins ; cAMP ; phosphatidyl inositol ; cyclooxygenase ; arachidonic acid ; PDGF ; retinoic acid ; TGFβ ; LPA ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The bioactive lipid lysohosphatidic acid is besides a strong mitogen for quiescent fibroblasts, a potent inducer of phenotypic transformation on normal rat kidney cells. The lysophosphatidic acid induced loss of densityarrest is strongly inhibited by bradykinin. Although their effects on normal rat kidney cell proliferation are opposite, bradykinin mimics many of the intracellular effects induced upon lysophosphatidic acid receptor activation, including phosphoinositide turnover, Ca2+-mobilization and arachidonic acid release. Bradykinin does not counteract the lysophosphatidic acid induced reduction of cAMP levels in normal rat kidney cells. However, bradykinin inhibits the lysophosphatidic acid and other growth factor induced phenotypic transformation through the induction of a so far uncharacterized prostaglandin G/H synthase product. The growth inhibitory effect of bradykinin is limited to density-arrested cells, while upon prolonged treatment bradykinin itself is capable to induce the loss of densitydependent growth control. It is concluded that bradykinin is a bifunctional regulator of normal rat kindney cell proliferation and that its inhibitory effects are midiated via induction of a prostaglandin dervative.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240560408
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