Small Molecules Facilitate the Reprogramming of Mouse Fibroblasts into Pancreatic Lineages Scientists describe a stepwise method in which pluripotency reprogramming factors were transiently expressed in fibroblasts in conjunction with a unique combination of soluble molecules to generate definitive endoderm-like cells that did not pass through a pluripotent state. The resulting pancreatic progenitor-like cells could mature into cells of all three pancreatic lineages in vivo, including functional, insulin-secreting β-like cells that help to ameliorate hyperglycemia. [Cell Stem Cell] Abstract | Graphical Abstract | Press Release The Two Active X Chromosomes in Female ESCs Block Exit from the Pluripotent State by Modulating the ESC Signaling Network Using embryonic stem cells with distinct sex chromosome compositions as a model system, scientists showed that two X chromosomes stabilize the naive pluripotent state by inhibiting MAPK and Gsk3 signaling and stimulating the Akt pathway. [Cell Stem Cell] Abstract | Graphical Abstract Isolation of Single-Base Genome-Edited Human iPS Cells without Antibiotic Selection Researchers developed an efficient method to capture rare mutational events, enabling isolation of mutant lines with single-base substitutions without antibiotic selection. This method facilitates efficient induction or reversion of mutations associated with human disease in isogenic human induced pluripotent stem cells. [Nat Methods] Abstract Derivation and Characterization of Mouse Embryonic Stem Cells from Permissive and Nonpermissive Strains The authors describe a protocol for efficient derivation of germline-competent mouse embryonic stem cells from any mouse strain, including strains previously deemed nonpermissive. They provide a protocol that is generally applicable to most inbred strains, as well as a variant for nonpermissive strains. [Nat Protoc] Abstract Oct4 Is Required for Lineage Priming in the Developing Inner Cell Mass of the Mouse Blastocyst Investigators explored the role of Oct4 in blastocyst formation and specification of epiblast versus primitive endoderm lineages using conditional genetic deletion. Experiments involving mouse embryos deficient for both maternal and zygotic Oct4 suggest that it is dispensable for zygote formation, early cleavage and activation of Nanog expression. [Development] Abstract | Full Article Growth and Proliferation of Human Embryonic Stem Cells on Fully Synthetic Scaffolds Based on Carbon Nanotubes Scientists showed an industrially scalable and inexpensive method of fabricating entirely synthetic, non-xenogeneic carbon nanotube-based scaffolds by vacuum filtration for the culture of human embryonic stem cells. [ACS Appl Mater Interfaces] Abstract | Press Release ONSL and OSKM Cocktails Act Synergistically in Reprogramming Human Somatic Cells into Induced Pluripotent Stem Cells Researchers compared the reprogramming efficiency of two different polycistronic genes, OCT4, NANOG, SOX2 and LIN28 (ONSL) and OCT4, SOX2, KLF4 and cMYC (OSKM) placed in the same retrovector backbone. [Mol Hum Reprod] Abstract A Single-Cell and Feeder-Free Culture System for Monkey Embryonic Stem Cells Researchers report a new single-cell and feeder-free culture system for primate pluripotent stem cells, the key feature of which is an originally formulated serum-free medium containing FGF and activin. [PLoS One] Full Article Win a $25 Amazon Gift Card! Connexon Creative is evaluating reader interest in a new social media platform. Fill out this quick survey for your chance to win 1 of 4 $25 gift cards! Take survey here |