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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nanog is a key transcription regulatory molecule that plays an important role in maintaining stem cell pluripotency. However, the molecular features and transcription regulation of the NANOG gene in domestic animals are not well investigated. In this study, the 751-base pairs (bp) fragment of the proximal region of the goat NANOG promoter (GNP), which has a 572-bp promoter sequence retaining multiple transcription binding sites and a 179-bp 5' untranslated region of the goat NANOG gene, was cloned and characterized. The recombinant construct of pGNP-EGFP (enhanced green fluorescent protein) was solely activated in pluripotent cells and could be upregulated by the Oct4/Sox2 complex. The construct was stably transfected into goat fetal fibroblast (GFF) cells that were then used as the recipient cells to generate the induced pluripotent stem (iPS) cells. GNP-directed EGFP expression could be used to monitor the progression of cell reprogramming and the formation of iPS cells. The pGNP-EGFP construct was also delivered into goat oocytes cultured in vitro by microinjection. Interestingly, NANOG expression pattern in early stage goat embryos matured in vitro was asymmetrical. In two-cell embryos, the expression level of NANOG was uneven with one blastomere expressing EGFP and the next blastomere with no expression of EGFP. This was also observed in four-cell embryos. This asymmetrical expression may be due to the heterozygous expression of NANOG because of the quality of embryos and the culture environment. In conclusion, the GNP-EGFP reporter system represents a useful tool to monitor endogenous NANOG activation and for research with goat pluripotent stem cells.
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PMID:Characterization of the proximal region of the goat NANOG promoter that is used for monitoring cell reprogramming and early embryo development. 2418 13

Various somatic stem cells divide asymmetrically; however, it is not known whether embryonic stem cells (ESCs) divide symmetrically or asymmetrically, not only while maintaining an undifferentiated state but also at the onset of differentiation. In this study, we observed single ESCs using time-lapse imaging and compared sister cell pairs derived from the same mother cell in either the maintenance or differentiation medium. Mouse ESCs were cultured on E-cadherin-coated glass-based dishes, which allowed us to trace single cells. The undifferentiated cell state was detected by green fluorescent protein (GFP) expression driven by the Nanog promoter, which is active only in undifferentiated cells. Cell population analysis using flow cytometry showed that the peak width indicating distribution of GFP expression broadened when cells were transferred to the differentiation medium compared to when they were in the maintenance medium. This finding suggested that the population of ESCs became more heterogeneous at the onset of differentiation. Using single-cell analysis by time-lapse imaging, we found that although the total survival ratio decreased by changing to differentiation medium, the one-live-one-dead ratio of sister cell pairs was smaller compared with randomly chosen non-sister cell pairs, defined as an unsynchronized cell pair control, in both media. This result suggested that sister cell pairs were more positively synchronized with each other compared to non-sister cell pairs. The differences in interdivision time (the time interval between mother cell division and the subsequent cell division) between sister cells was smaller than that between non-sister cell pairs in both media, suggesting that sister cells divided synchronously. Although the difference in Nanog-GFP intensity between sister cells was smaller than that between non-sister cells in the maintenance medium, it was the same in differentiation medium, suggesting asymmetrical Nanog-GFP intensity. These data suggested that ESCs may divide asymmetrically at the onset of differentiation resulting in heterogeneity.
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PMID:Asymmetricity Between Sister Cells of Pluripotent Stem Cells at the Onset of Differentiation. 2933 19