Chang Nam Hwang

Comparative Study of P19 EC Stem Cell Differentiation in between Conventional Hanging Drop and the Zebrafish Chorion as a Bio-derived Material

Various materials including glass and polymers have been widely used for stem cell culture due to their biocompatibility. However, the roles of these materials are fundamentally limited because they cannot realize or imitate the complex biological functions of living tissues, except in very simple cases. Here, the development of a bio-derived material suitable for stem cell culture and improvement of differentiation efficiency to specific cell lineages with no stimulating agents by using a chorion obtained from a fertilized zebrafish egg through the removal of the yolk and embryonic cell mass from the egg is reported. Mouse P19 EC stem cells introduced into the empty chorion form a uniform embryoid body (EB) without addition of any inducing agent. It is demonstrated that the zebrafish chorion with nanopores improves efficiencies greatly in the EB formation, cell proliferation, and lineage-specific differentiations compared to those of the conventional hanging drop culture method.

Dual Reporter Genes Enabling Cell Tracing with Viable and Reliable Selection of Various Cell Types

Dual reporter genes driven by either a ubiquitous cytomegalovirus (CMV) or a neuro-specific tubulin α1 promoter (Tα1) were constructed. The new genes, CMV (pCMV-GL) or Tα1 promoter-driven GFP–LacZ (pTα1-GL), robustly expressed the fused GFP–LacZ protein reporting constitutive expressions in various cell types including CHO cells, loach and chicken embryos, and neuro-specific expression in differentiating mouse embryonic stem cells, respectively. The dual reporter genes thus provide a versatile tool for the studies of gene expression, cell lineage within the embryo and possibly the fate of stem cells in transplantation experiment, thus facilitating different analyses depending on the experimental purposes.

Erratum: Dual reporter genes enabling cell tracing with viable and reliable selection of various cell types (Biotechnology Letters (2006) 28, (287-293) DOI: 10.1007/s10529-005-5715-9)

Dual reporter genes driven by either a ubiquitous cytomegalovirus (CMV) or a neuro-specific tubulin alpha1 promoter (Talpha1) were constructed. The new genes, CMV (pCMV-GL) or Talpha1 promoter-driven GFP-LacZ (pTalpha1-GL), robustly expressed the fused GFP-LacZ protein reporting constitutive expressions in various cell types including CHO cells, loach and chicken embryos, and neuro-specific expression in differentiating mouse embryonic stem cells, respectively. The dual reporter genes thus provide a versatile tool for the studies of gene expression, cell lineage within the embryo and possibly the fate of stem cells in transplantation experiment, thus facilitating different analyses depending on the experimental purposes.