Biomedical subjects

J S Draper

Publications and source records attributed to J S Draper.

3 recordsLinked to original sources

PubMed2007

Improved embryonic stem cell technologies.

Murine embryonic stem (ES) cells have become an indispensable tool for investigating genetic function both in vitro and, importantly, in vivo. Recent advances, including tetraploid aggregation, new site-specific recombinases and RNAi, have enabled more sophisticated manipulation of the ES cell genome. For instance, it is now possible to control gene expression in both a temporally and spatially restricted manner. Such new technologies are answering complex questions surrounding the function and interaction of an increasing number of genes. This chapter will review both the history and recent technological progress that has been made in mouse ES cell derivation, genetic manipulation and the generation of ES cell-derived chimaeric animals.

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PubMed2005

Embryonic stem (ES) cells and embryonal carcinoma (EC) cells: opposite sides of the same coin.

Embryonal carcinoma (EC) cells are the stem cells of teratocarcinomas, and the malignant counterparts of embryonic stem (ES) cells derived from the inner cell mass of blastocyst-stage embryos, whether human or mouse. On prolonged culture in vitro, human ES cells acquire karyotypic changes that are also seen in human EC cells. They also 'adapt', proliferating faster and becoming easier to maintain with time in culture. Furthermore, when cells from such an 'adapted' culture were inoculated into a SCID (severe combined immunodeficient) mouse, we obtained a teratocarcinoma containing histologically recognizable stem cells, which grew out when the tumour was explanted into culture and exhibited properties of the starting ES cells. In these features, the 'adapted' ES cells resembled malignant EC cells. The results suggest that ES cells may develop in culture in ways that mimic changes occurring in EC cells during tumour progression.

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PubMed2002

Preimplantation human embryos and embryonic stem cells show comparable expression of stage-specific embryonic antigens.

Cell-surface antigens provide invaluable tools for the identification of cells and for the analysis of cell differentiation. In particular, stage-specific embryonic antigens that are developmentally regulated during early embryogenesis are widely used as markers to monitor the differentiation of both mouse and human embryonic stem (ES) cells and their malignant counterparts, embryonic carcinoma (EC) cells. However, there are notable differences in the expression patterns of some such markers between human and mouse ES/EC cells, and hitherto it has been unclear whether this indicates significant differences between human and mouse embryos, or whether ES/EC cells correspond to distinct cell types within the early embryos of each species. We now show that human ES cells are characterized by the expression of the cell-surface antigens, SSEA3, SSEA4, TRA-1-60, and TRA-1-81, and by the lack of SSEA1, and that inner cell mass cells of the human blastocyst express a similar antigen profile, in contrast to the corresponding cells of the mouse embryo.

Animals↗