The Notch signaling pathway plays important roles in cell-fate determination during embryonic development and adult life. In this study, we focus on the role of Notch signaling in governing cell-fate choices in human embryonic stem cells (hESCs). Using genetic and pharmacological approaches, we achieved both blockade and conditional activation of Notch signaling in several hESC lines. We report...

VegT and beta-Catenin are key players in the hierarchy of factors that are required for induction and patterning of mesendoderm in Xenopus embryogenesis. By descending the genetic cascades, cells lose their pluripotent status and are determined to differentiate into distinct tissues. Mammalian Oct-3/4, a POU factor of subclass V (POU-V), is required for the maintenance of pluripotency of embryo...

The efficient generation of hepatocytes from human pluripotent stem cells (hPSCs) requires the induction of a proper endoderm population, broadly characterized by the expression of the cell surface marker CXCR4. Strategies to identify and isolate endoderm subpopulations predisposed to the liver fate do not exist. In this study, we generated mouse monoclonal antibodies against human embryonic st...

The inconsistency of efficiency in murine embryonic stem cell (ESC) production might be associated with the differences in preparation and cryopreservation of the feeder cell layer. As the cryopreservation of mouse embryonic fibroblast (MEF) declined the quality of MEF as feeder cell layer, an effective protocol should be determined to produce murine ESC on frozen-thawed feeder cell layer as ef...

Teratomas are bulky lesions that rarely occur in the head and neck regions.They are composed of tissues from all germ layers with varying degrees of differentiation. They arise from pluripotential stem cells and ectopic embryonic non-germ cells. The most common sites of occurrence in the head and neck are the cervical region and the nasopharynx. Three cases of these tumors are reported here...

Embryonic development is a complex dynamic process where spatial organization of molecular signals direct stem cells into the 3 germ layers. Recapitulating this process in vitro will greatly facilitate the mechanistic understanding of embryonic development. However, current models are unable to reproduce the complex developmental environment adequately. To realize the aim of building a complex ...

A master plan for the early development of all chordates is proposed. The radial symmetry of the chordate ovum is changed at or after fertilization into a bilateral symmetry by an external signal. Until now two alternative triggers, sperm entry and gravity, have been demonstrated. It is suggested that a correlation exists between the amount of yolk stored in the egg and the mechanism used for a...

Early development occurs in a highly organized and orchestrated manner and has long attracted the interest of developmental biologists and embryologists. Cell lineage, or the study of the developmental differentiation [4] of a blastomere [5], involves tracing a particular cell ( blastomere [5]) forward from its position in one of the three germ layers [6]. Labeling individual cells within their...