Site-specific recombinases are being developed as tools for "in vivo" genetic engineering because they can catalyze precise excisions, integrations, inversions, or translocations of DNA between their distinct recognition target sites. Here it is demonstrated that Flp recombinase can effectively mediate site-specific excisional recombination in mouse embryonic stem cells, in differentiating embr...

A chimera is an animal that has two or more populations of genetically distinct cells that originated in different embryos, fetuses, or individuals of the same or different species. During recent decades, embryos, the inner cell mass (ICM), teratocarcinoma stem cells, embryonal carcinoma stem cells, embryonic stem (ES) cells (ESCs), primordial germ cells, spermatogonial stem cells, extraembryon...

We have been investigating the pathogenesis of teratocarcinomas, particularly the development of the adult, apparently benign, differentiated struc tures common to them. Although nothing is known concerning the mechanism of the changes involved, we have demonstrated that the differen tiated tissues of a teratocarcinoma are derived from embryonic cell types found within the tumor (12). These emb...

Two mouse embryonal carcinoma cell lines, PCC.4 aza-1 and F9, have been grown in serum-free F-12 medium supplemented with Pedersen fetuin, insulin, transferrin, and 2-mercaptoethanol. This medium supports long-term growth of both cell lines. When these cells are transferred from medium containing serum to this serum-free medium, growth continues without any detectable lag. PCC.4 aza-1 grown in ...

Hexamethylene bisacetamide (HMBA) induces in vitro the cytodifferentiation of PCC3/A/1 mouse embryonal carcinoma (EC) cells. In EC cells, actin is associated with surface structures but microfilament bundles are not seen. After 2 days of HMBA treatment, rounded EC cells are converted to flat adhesive ones with a developed cytoskeleton containing actin and tropomyosin. The ratio of actin to tota...

The ability to form teratomas in vivo containing multiple somatic cell types is regarded as functional evidence of pluripotency for human pluripotent stem cells (hPSCs). Since the Teratoma assay is animal dependent, laborious, and only qualitative, the PluriTest and the hPSC ScoreCard assay have been developed as in vitro alternatives. Here we compared normal hPSCs, induced hPSCs (hiPSCs) with ...

BACKGROUND There is only limited knowledge about gene expression in human testicular germ cell tumors of adolescents and adults (TGCTs), and, in particular in its preinvasive stage intratubular germ cell neoplasia unclassified (IGCNU). MATERIALS AND METHODS Global gene expression was studied in 10 invasive human testicular germ cell tumors (TGCTs), 7 intratubular germ cell neoplasia unclassif...

Neural basic helix-loop-helix transcription factors (bHLHs) control many aspects of neurogenesis, such as proliferation, fate determination, and differentiation. We have previously shown that the promyogenic cell surface receptor Cdo modulates the Cdc42 and p38 mitogen-activated protein kinase (MAPK) pathways via a direct association with two scaffold-type proteins, JLP and Bnip-2, to regulate ...