Investigating the molecular mechanisms controlling the in vivo developmental program postembryogenesis is challenging and time consuming. However, the developmental program can be partly recapitulated in vitro by the use of cultured embryonic stem cells (ESCs). Similar to the totipotent cells of the inner cell mass, gene expression and morphological changes in cultured ESCs occur hierarchically...

The feeder layer constitutes a prerequisite for the undifferentiated proliferation of human embryonic stem (hES) cells in vitro. However, a few feeders have been reported to be nonsupportive in nature, suggesting that these feeders exhibit a different transcriptome and proteome, in comparison to their supportive counterparts. In an attempt to identify factors required for undifferentiated growt...

Mechanical forces are critical to embryogenesis, specifically, in the lineage-specification gastrulation phase, whereupon the embryo is transformed from a simple spherical ball of cells to a multi-layered organism, containing properly organized endoderm, mesoderm, and ectoderm germ layers. Several reports have proposed that such directed and coordinated movements of large cell collectives are d...

Liver X receptor (LXR) beta regulates cholesterol levels in the brain and is essential for maintenance of motor neurons in the spinal cord and dopaminergic neurons in the substantia nigra. Here, we have examined the expression pattern of LXRbeta protein in the cerebral cortex and looked for defects in cortical development in LXRbeta knockout (LXRbeta(-/-)) mice. LXRbeta protein was widely expre...

In vitro study of primary neuronal cultures allows for quantitative analyses of neurite outgrowth. In order to study how genetic alterations affect neuronal process outgrowth, shRNA or cDNA constructs can be introduced into primary neurons via chemical transfection or viral transduction. However, with primary cortical cells, a heterogeneous pool of cell types (glutamatergic neurons from differe...

background: since embryonic stem (es) cells have the dual ability to proliferate indefinitely and differentiate into multiple tissue types, es cells could potentially provide an unlimited cell supply for human transplantation. objective: in order to study the differentiation of mouse embryonic stem (mes) cells, they were cultured in suspension by using es media without leukemia inhibitory facto...

Mouse morulae, blastocysts, and embryonic and extraembryonic tissue layers were examined for benzo[a]-pyrene metabolism by cytochrome P-450, using the sister chromatid exchange assay. Benzo[a]pyrene exposure in vitro increased sister chromatid exchanges in blastocysts of all genetically responsive mice examined [BALB/cDub, C3H/AnfCum, and outbred Dub:(ICR) strains] but not blastocysts of the no...

Mature adult tissues contain stem cells that express many genes normally associated with the early stage of embryonic development, when maintained in appropriate environments. Cells procured from adult tissues representative of the three germ layers (spinal cord, muscle, and lung), each exhibiting the potential to mature into cells representative of all three germ layers. Cells isolated from ad...

Pluripotent stem cells possess the capacity for self-renewal and the ability to differentiate into all cell types of the three embryonic germ layers. Accordingly, given their potential use in regenerative medicine, they have long attracted the attention of researchers. Embryonic stem cells (ESCs) represent the model pluripotent stem cell population. However, the use of ESCs in regenerative ther...