20 research outputs found
Germline Competent Pluripotent Mouse Stem Cells Generated by Plasmid Vectors
<p>We developed nonintegrated methods to reprogram mouse embryonic fibroblast (MEF) cells into induced pluripotent stem cells (iPSCs) using pig pOct4, pSox2, and pc-Myc as well as human hKLF4, hAID, and hTDG that were carried by plasmid vectors. The 4F method employed pOct4, pSox2, pc-Myc, and hKLF4 to derive iPSC clones with naive embryonic stem cell (ESC)-like morphology. These 4F clones expressed endogenous mouse Nanog protein and could generate chimeras. In addition to the four conventional reprogramming factors used in the 4F method, hAID and hTDG were utilized in a 6F method to increase the conversion efficiency of reprogramming by approximately five-fold. One of the 6F plasmid derived iPSC (piPSC) clones was shown to be germline transmission competent.</p
Insight into the Reactivity and Electronic Structure of Dinuclear Dinitrosyl Iron Complexes
A combination of N/S/Fe K-edge X-ray
absorption spectroscopy (XAS), X-ray diffraction data, and density
functional theory (DFT) calculations provides an efficient way to
unambiguously delineate the electronic structures and bonding characters
of Fe–S, N–O, and Fe–N bonds among the direduced-form
Roussin’s red ester (RRE) [Fe<sub>2</sub>(μ-SPh)<sub>2</sub>(NO)<sub>4</sub>]<sup>2–</sup>(<b>1</b>) with
{FeÂ(NO)<sub>2</sub>}<sup>10</sup>-{FeÂ(NO)<sub>2</sub>}<sup>10</sup> core, the reduced-form RRE [Fe<sub>2</sub>(μ-SPh)<sub>2</sub>(NO)<sub>4</sub>]<sup>−</sup>(<b>3</b>) with {FeÂ(NO)<sub>2</sub>}<sup>9</sup>-{FeÂ(NO)<sub>2</sub>}<sup>10</sup> core, and
RRE [Fe<sub>2</sub>(μ-SPh)<sub>2</sub>(NO)<sub>4</sub>] (<b>4</b>) with {FeÂ(NO)<sub>2</sub>}<sup>9</sup>-{FeÂ(NO)<sub>2</sub>}<sup>9</sup> core. The major contributions of highest occupied molecular
orbital (HOMO) 113α/β in complex <b>1</b> is related
to the antibonding character between FeÂ(d) and FeÂ(d), FeÂ(d), and S
atoms, and bonding character between FeÂ(d) and NOÂ(Ï€*). The effective
nuclear charge (<i><i>Z</i></i><sub>eff</sub>)
of Fe site can be increased by removing electrons from HOMO to shorten
the distances of Fe···Fe and Fe–S from <b>1</b> to <b>3</b> to <b>4</b> or, in contrast, to
increase the Fe–N bond lengths from <b>1</b> to <b>3</b> to <b>4</b>. The higher IR ν<sub>NO</sub> stretching
frequencies (1761, 1720 cm<sup>–1</sup> (<b>4</b>), 1680,
1665 cm<sup>–1</sup> (<b>3</b>), and 1646, 1611, 1603
cm<sup>–1</sup> (<b>1</b>)) associated with the higher
transition energy of N<sub>1s</sub> →σ*Â(NO) (412.6 eV
(<b>4</b>), 412.3 eV (<b>3</b>), and 412.2 eV (<b>1</b>)) and the higher <i><i>Z</i></i><sub>eff</sub> of Fe derived from the transition energy of Fe<sub>1s</sub> →
Fe<sub>3d</sub> (7113.8 eV (<b>4</b>), 7113.5 eV (<b>3</b>), and 7113.3 eV (<b>1</b>)) indicate that the N–O bond
distances of these complexes are in the order of <b>1 > 3 >
4</b>. The N/S/Fe K-edge XAS spectra as well as DFT computations
reveal the reduction of complex <b>4</b> yielding complex <b>3</b> occurs at Fe, S, and NO; in contrast, reduction mainly occurs
at Fe site from complex <b>3</b> to complex <b>1</b>
Insight into the Reactivity and Electronic Structure of Dinuclear Dinitrosyl Iron Complexes
A combination of N/S/Fe K-edge X-ray
absorption spectroscopy (XAS), X-ray diffraction data, and density
functional theory (DFT) calculations provides an efficient way to
unambiguously delineate the electronic structures and bonding characters
of Fe–S, N–O, and Fe–N bonds among the direduced-form
Roussin’s red ester (RRE) [Fe<sub>2</sub>(μ-SPh)<sub>2</sub>(NO)<sub>4</sub>]<sup>2–</sup>(<b>1</b>) with
{FeÂ(NO)<sub>2</sub>}<sup>10</sup>-{FeÂ(NO)<sub>2</sub>}<sup>10</sup> core, the reduced-form RRE [Fe<sub>2</sub>(μ-SPh)<sub>2</sub>(NO)<sub>4</sub>]<sup>−</sup>(<b>3</b>) with {FeÂ(NO)<sub>2</sub>}<sup>9</sup>-{FeÂ(NO)<sub>2</sub>}<sup>10</sup> core, and
RRE [Fe<sub>2</sub>(μ-SPh)<sub>2</sub>(NO)<sub>4</sub>] (<b>4</b>) with {FeÂ(NO)<sub>2</sub>}<sup>9</sup>-{FeÂ(NO)<sub>2</sub>}<sup>9</sup> core. The major contributions of highest occupied molecular
orbital (HOMO) 113α/β in complex <b>1</b> is related
to the antibonding character between FeÂ(d) and FeÂ(d), FeÂ(d), and S
atoms, and bonding character between FeÂ(d) and NOÂ(Ï€*). The effective
nuclear charge (<i><i>Z</i></i><sub>eff</sub>)
of Fe site can be increased by removing electrons from HOMO to shorten
the distances of Fe···Fe and Fe–S from <b>1</b> to <b>3</b> to <b>4</b> or, in contrast, to
increase the Fe–N bond lengths from <b>1</b> to <b>3</b> to <b>4</b>. The higher IR ν<sub>NO</sub> stretching
frequencies (1761, 1720 cm<sup>–1</sup> (<b>4</b>), 1680,
1665 cm<sup>–1</sup> (<b>3</b>), and 1646, 1611, 1603
cm<sup>–1</sup> (<b>1</b>)) associated with the higher
transition energy of N<sub>1s</sub> →σ*Â(NO) (412.6 eV
(<b>4</b>), 412.3 eV (<b>3</b>), and 412.2 eV (<b>1</b>)) and the higher <i><i>Z</i></i><sub>eff</sub> of Fe derived from the transition energy of Fe<sub>1s</sub> →
Fe<sub>3d</sub> (7113.8 eV (<b>4</b>), 7113.5 eV (<b>3</b>), and 7113.3 eV (<b>1</b>)) indicate that the N–O bond
distances of these complexes are in the order of <b>1 > 3 >
4</b>. The N/S/Fe K-edge XAS spectra as well as DFT computations
reveal the reduction of complex <b>4</b> yielding complex <b>3</b> occurs at Fe, S, and NO; in contrast, reduction mainly occurs
at Fe site from complex <b>3</b> to complex <b>1</b>
Competency of Aggregated (3×) Cloned Porcine Blastocysts to Derive ES Cell Lines in Various Culture Media.
<p>Competency of Aggregated (3×) Cloned Porcine Blastocysts to Derive ES Cell Lines in Various Culture Media.</p
Alkaline phosphatase (AP) activity and karyotypes of ntES cells derived from aggregated cloned blastocysts.
<p>(a) A phase-contrast image of ntES cell colony with positive AP activity at passage 3. (b) Karyotyping by Giemsa staining of ntES cell line PES1 at passage 20 with 75% of normal karyotype, and (c) PES3 line at passage 28 with a normal karyotype ratio of 85%. Scale bar = 100 μm.</p
Immunofluorescence staining of pluripotency markers in ntES cell colonies derived from aggregated cloned embryos.
<p>Expressions of pluripotency markers (Oct4, Nanog and Sox2) are shown (red) in PES3 at passage 15 (left panel) and PES1 at passage 10 (right panel). Nuclei are stained with DAPI (blue). Scale bars = 100 μm.</p
Competency of Aggregated Cloned and Parthenogenetic (PA) Porcine Blastocysts for Derivation of ES Cell Colonies.
<p>Competency of Aggregated Cloned and Parthenogenetic (PA) Porcine Blastocysts for Derivation of ES Cell Colonies.</p
Formation of ntES cell colonies derived from the blastocyst embryos of the 3× cloned embryos.
<p>(a) A 3× blastocyst embryo (day 7) and (b) embryonal outgrowths with clearly ICM cells (red arrow) after culture for 5–8 days. (c) Typical morphology of a putative porcine ntES cell colony after passage. Scale bar = 100 μm.</p
Differentiation of ntES cells in embryoid bodies (EB) and RT-PCR detection of genes typical for three germ layers.
<p>(a) Light microscopic images of EB cultured for 10 days. (b) Expressions of the genes representing all three germ layers, GATA4 (endoderm), β-III tubulin (ectoderm), and BMP-4 (mesoderm) in EB derived from PES1 (A), PES3 (B), and the negative control is represented by undifferentiated PES3 cells (C). Scale bars = 100 μm.</p
Competency of Aggregated (3×) Cloned Porcine Blastocysts to Derive ES Cell Lines in Various Culture Media.
<p>Competency of Aggregated (3×) Cloned Porcine Blastocysts to Derive ES Cell Lines in Various Culture Media.</p