Ascorbic Acid Prevents Loss of Dlk1–Dio3 Imprinting and Facilitates Generation of All-Induced Pluripotent Stem Cell Mice from Terminally Differentiated B Cells Here, researchers show that reprogramming in the presence of ascorbic acid attenuates hypermethylation of Dlk1–Dio3 by enabling a chromatin configuration that interferes with binding of the de novo DNA methyltransferase Dnmt3a. [Nat Genet] Abstract Chromatin-Modifying Enzymes as Modulators of Reprogramming To address how chromatin-modifying proteins influence reprogramming, researchers used short hairpin RNAs to target genes in DNA and histone methylation pathways, and identified positive and negative modulators of induced pluripotent stem cell generation. [Nature] Abstract Genetic Regulators of a Pluripotent Adult Stem Cell System in Planarians Identified by RNAi and Clonal Analysis Researchers utilized transcriptional profiling to identify planarian genes expressed in adult proliferating, regenerative cells. Researchers also developed quantitative clonal analysis methods for expansion and differentiation of adult pluripotent stem cell descendants that, together with RNAi, revealed gene roles in stem cell biology. [Cell Stem Cell] Abstract | Press Release Low Incidence of DNA Sequence Variation in Human Induced Pluripotent Stem Cells Generated by Nonintegrating Plasmid Expression Here investigators report the whole-genome sequencing of three human induced pluripotent stem cell lines derived from two cell types of an adult donor by episomal vectors. [Cell Stem Cell] Abstract Distinct Regulatory Mechanisms and Functions for p53-Activated and p53-Repressed DNA Damage Response Genes in Embryonic Stem Cells p53 is critical in regulating the differentiation of embryonic stem (ES) and induced pluripotent stem cells. Here, investigators report a whole-genome study of p53-mediated DNA damage signaling in mouse ES cells. [Mol Cell] Abstract AMD1 Is Essential for ESC Self-Renewal and Is Translationally Down-Regulated on Differentiation to Neural Precursor Cells Scientists describe a new role for Amd1 (adenosyl methionine decarboxylase), a key enzyme in the polyamine synthesis pathway, in regulating both embryonic stem cell (ESC) self-renewal and differentiation to the neural lineage. [Genes Dev] Abstract | Press Release Wnt/β-Catenin Signaling Promotes Differentiation, Not Self-Renewal, of Human Embryonic Stem Cells and Is Repressed by Oct4 Researchers demonstrate that OCT4 represses β-catenin signaling during self-renewal and that targeted knockdown of OCT4 activates β-catenin signaling in human embryonic stem cells. [Proc Natl Acad Sci USA] Abstract Contribution of Hepatic Lineage Stage-Specific Donor Memory to the Differential Potential of Induced Mouse Pluripotent Stem Cells (iPSC) Here investigators addressed a contribution of a lineage stage-specific donor cell memory in modulating the functional properties of iPSCs. [Stem Cells] Abstract Quantitative Proteomic Analysis of Mouse Embryonic Fibroblasts and Induced Pluripotent Stem Cells Using 16O/18O Labeling Here researchers report the development and application of an integrated quantitative proteomics platform for investigating differences in protein expressions between mouse embryonic fibroblasts (MEF) and MEF-derived induced pluripotent stem cells. [J Proteome Res] Abstract Feeder-Free and Serum-Free Production of Hepatocytes, Cholangiocytes, and Their Proliferating Progenitors from Human Pluripotent Stem Cells: Application to Liver-Specific Functional and Cytotoxic Assays Researchers have established a serum- and feeder-free culture system for the efficient differentiation of multifunctional hepatocytes from human embryonic stem cells and three entirely different induced pluripotent stem cells without cell sorting and gene manipulation. [Cell Reprogam] Abstract |