30 research outputs found

    Reprogrammed Transcriptome in Rhesus-Bovine Interspecies Somatic Cell Nuclear Transfer Embryos

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    Global activation of the embryonic genome (EGA), one of the most critical steps in early mammalian embryo development, is recognized as the time when interspecies somatic cell nuclear transfer (iSCNT) embryos fail to thrive.In this study, we analyzed the EGA-related transcriptome of rhesus-bovine iSCNT 8- to 16-cell embryos and dissected the reprogramming process in terms of embryonic gene activation, somatic gene silencing, and maternal RNA degradation. Compared with fibroblast donor cells, two thousand and seven genes were activated in iSCNT embryos, one quarter of them reaching expression levels comparable to those found in in vitro fertilized (IVF) rhesus embryos. This suggested that EGA in iSCNT embryos had partially recapitulated rhesus embryonic development. Eight hundred and sixty somatic genes were not silenced properly and continued to be expressed in iSCNT embryos, which indicated incomplete nuclear reprogramming. We compared maternal RNA degradation in bovine oocytes between bovine-bovine SCNT and iSCNT embryos. While maternal RNA degradation occurred in both SCNT and iSCNT embryos, we saw more limited overall degradation of maternal RNA in iSCNT embryos than in SCNT embryos. Several important maternal RNAs, like GPF9, were not properly processed in SCNT embryos.Our data suggested that iSCNT embryos are capable of triggering EGA, while a portion of somatic cell-associated genes maintain their expression. Maternal RNA degradation seems to be impaired in iSCNT embryos. Further understanding of the biological roles of these genes, networks, and pathways revealed by iSCNT may expand our knowledge about cell reprogramming, pluripotency, and differentiation

    Comparative maturation of cynomolgus monkey oocytes in vivo and in vitro

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    BACKGROUND: In vitro maturation (IVM) of oocytes followed by fertilization in vitro (IVF) and embryo transfer offers an alternative to conventional IVF treatment that minimises drug administration and avoids ovarian hyperstimulation. However, the technique is less efficient than maturation in vivo. In the present study, a non-human primate model was used to address the hypothesis that the number of oocytes is increased and their nuclear and cytoplasmic maturity after IVM are improved when maturation is initiated in vivo by priming with hCG. METHODS: Young, adult cynomolgus monkeys were given recombinant human (rh) gonadotropins to stimulate the development of multiple follicles, and oocytes were aspirated 0, 12, 24, or 36 h after injection of an ovulatory dose of rhCG. The nuclear status of oocytes was determined at the time of recovery and after culture for a total elapsed time of 40–44 hours after hCG. RESULTS: Priming with hCG significantly increased the number of oocytes harvested, especially after delaying aspiration for 24 h or longer. Nuclear maturation after the full period in culture was also enhanced by priming: 71.5, 83.6, and 94.6% of oocytes collected at 0, 12, and 24 h hCG had progressed to MII by the end of the culture period, compared to 87.8% of oocytes that were retrieved at 36 h. A large proportion of oocytes reaching the MII stage had either or both abnormal spindles (>40%) and misaligned chromosomes (>60%), judging by immunofluorescence microscopy, but these abnormalities were independent of culture time. The mitochondria were evenly distributed throughout the cytoplasm at all stages of maturation. Importantly, there was no microscopic evidence that the duration of culture had any injurious effects on the cells. CONCLUSION: In conclusion, the evidence supports this non-human primate as a model for human IVM and the practice of priming with hCG to promote developmental potential

    Differential effects of alcohol and its metabolite acetaldehyde on vascular smooth muscle cell Notch signaling and growth

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    Alcohol (EtOH) consumption can variously affect cardiovascular disease. Our aim was to compare the effects of EtOH and its primary metabolite acetaldehyde (ACT) on vascular smooth muscle Notch signaling and cell growth, which are important for atherogenesis. Human coronary artery smooth muscle cells (HCASMCs) were treated with EtOH (25 mM) or ACT (10 or 25 μM). As previously reported, EtOH inhibited Notch signaling and growth of HCASMCs. In contrast, ACT treatment stimulated HCASMC proliferation (cell counts) and increased proliferating cell nuclear antigen expression, concomitant with stimulation of Notch signaling, as determined by increased Notch receptor (N1 and N3) and target gene (Hairy-related transcription factor 1–3) mRNA levels. Interaction of the ligand with the Notch receptor initiates proteolytic cleavage by α- and γ-secretase, resulting in the release of the active Notch intracellular domain. Neither EtOH nor ACT had any significant effect on α-secretase activity. A fluorogenic peptide cleavage assay demonstrated almost complete inhibition by EtOH of Delta-like ligand 4-stimulated γ-secretase activity in solubilized HCASMCs (similar to the effect of the control inhibitor DAPT) but no effect of ACT treatment. EtOH, but not ACT, affected the association and distribution of the γ-secretase catalytic subunit presenilin-1 with lipid rafts, as determined by dual fluorescent labeling and confocal microscopic visualization. In conclusion, ACT stimulates vascular smooth muscle cell Notch signaling and growth, effects opposite to those of EtOH. These differential actions on vascular smooth muscle cells of EtOH and its metabolite ACT may be important in mediating the ultimate effects of drinking on cardiovascular disease

    Reversible Immunocontraception in Male Monkeys Immunized with Eppin

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    Various forms of birth control have been developed for women; however, there are currently few options for men. The development of male contraceptives that are effective, safe, and reversible is desired for family planning throughout the world. We now report contraception of male nonhuman primates (Macaca radiata) immunized with Eppin, a testis/epididymis-specific protein. Seven out of nine males 78%) developed high titers to Eppin, and all of these high-titer monkeys were infertile. Five out of seven (71%) high-anti-Eppin titer males recovered fertility when immunization was stopped. This study demonstrates that effective and reversible male immunocontraception is an attainable goal. This method of immunocontraception may be extended to humans
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