Technology of somatic cell nuclear transfer (SCNT) has been adapted worldwide to generate transgenic animals, although the traditional procedure relies largely on instrumental micromanipulation. In this study, we used the modified handmade cloning (HMC) established in cattle and pig to produce transgenic sheep with elevated levels of omega-3 (n−3) fatty acids. Codon-optimized nematode mfat-1 was inserted into a eukaryotic expression vector and was transferred into the genome of primary ovine fibroblast cells from a male Chinese merino sheep. Reverse transcriptase PCR, gas chromatography, and chromosome analyses were performed to select nuclear donor cells capable of converting omega-6 (n−6) into n−3 fatty acids. Blastocysts developed after 7 days of in vitro culture were surgically transplanted into the uterus of female ovine recipients of a local sheep breed in Xinjiang. For the HMC, approximately 8.9% (n  = 925) of reconstructed embryos developed to the blastocyst stage. Four recipients became pregnant after 53 blastocysts were transplanted into 29 naturally cycling females, and a total of 3 live transgenic lambs were produced. Detailed analyses on one of the transgenic lambs revealed a single integration of the modified nematode mfat-1 gene at sheep chromosome 5. The transgenic sheep expressed functional n−3 fatty acid desaturase, accompanied by more than 2-folds reduction of n−6/n−3 ratio in the muscle (p<0.01) and other major organs/tissues (p<0.05). To our knowledge, this is the first report of transgenic sheep produced by the HMC. Compared to the traditional SCNT method, HMC showed an equivalent efficiency but proved cheaper and easier in operation.

Photocatalytic CO 2 reduction reaction is believed to be a promising approach for CO 2 utilization. In this work, a noble metal-free photocatalytic system, composed of bis(terpyridine)iron(II) complexes and an organic thermally activated delayed fluorescence compound, has been developed for selective reduction of CO 2 to CO with a maximum turnover number up to 6320, 99.4% selectivity, and turnover frequency of 127 min −1 under visible−light irradiation in dimethylformamide/H 2 O solution. More than 0.3 mmol CO was generated using 0.05 μmol catalyst after 2 h of light irradiation. The apparent quantum yield was found to be 9.5% at 440 nm (180 mW cm −2 ). Control experiments and UV−vis−NIR spectroscopy studies further demonstrated that water strongly promoted the photocatalytic cycle and terpyridine ligands rather than Fe(II) were initially reduced during the photocatalytic process.

Epithelial-Mesenchymal Transition (EMT) is a critical step in the progression of cancer. Malignant melanoma, a cancer developed from pigmented melanocytes, metastasizes through an EMT-like process. Ten-eleven translocation (TET) enzymes, catalyzing the conversion of 5-methylcytosine (5mC) to 5-hydroxylmethylcytosine (5-hmC), are down regulated in melanoma. However, their roles in the progression and the EMT-like process of melanoma are not fully understood. Here we report that DNA methylation induced silencing of TET2 and TET3 are responsible for the EMT-like process and the metastasis of melanoma. TET2 and TET3 are down regulated in the TGF-β1-induced EMT-like process, and the knocking down of TET2 or TET3 induced this EMT-like process. A DNA demethylating agent antagonized the TGF-β-induced suppression of TET2 and TET3. Furthermore, a ChIP analysis indicated that enhanced recruitment of DNMT3A (DNA Methyltransferase 3A) is the mechanism by which TGF-β induces the silencing of TET2 and TET3. Finally, the overexpression of the TET2 C-terminal sequence partially rescues the TGF-β1-induced EMT-like process in vitro and inhibits tumor growth and metastasis in vivo. Hence, our data suggest an epigenetic circuitry that mediates the EMT activated by TGF-β. As an effector, DNMT3A senses the TGF-β signal and silences TET2 and TET3 promoters to induce the EMT-like process and metastasis in melanoma.

Endocrine therapies are the primary systemic intervention for patients with estrogen receptor-positive (ER þ ) breast cancer.

A discrete metallo–supramolecular assembly composed of six iron(II) cations and twelve redox–active terpyridine fragments has been developed for highly efficient visible–light–driven reduction of CO2 to CO with a TON of...

Currently, there are no methods available offering solutions to select and identify antibodies binding to a specific conformational epitope of an antigen. Here, we developed a method to allow epitope-directed antibody selection from a phage display library by photocrosslinking bound antibodies to a site that specifically incorporates a noncanonical amino acid, p-benzoyl-l-phenylalanine (pBpa), on the target antigen epitope. By one or two rounds of panning against antibody phage display libraries, those hits that covalently bind to the proximity site of pBpa on specific epitopes of target antigens after ultraviolet irradiation are enriched and selected. This method was applied to specific epitopes on human interleukin-1β and complement 5a. In both cases, more than one-third of hits identified bind to the target epitopes, demonstrating the feasibility and versatility of this method.

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The consecutive photoinduced electron transfer (ConPET) process of 1,2,3,5-Tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) in CO2 photoreduction to achieve powerful reducing species has been disclosed by activating a bis(terpyridine)ruthenium(II) complex bearing a high overpotential...