Development and validation of swine embryonic stem cells: a review

The establishment of embryonic cell lines from swine should be useful for studies of cell differentiation, developmental gene regulation and the production of transgenics. This paper summarizes the establishment of porcine (Sus scrofa) embryonic stem (ES) cell lines from preimplantation blastocysts and their ability to develop into normal chimaeras. ES cells can spontaneously differentiate into cystic embryoid bodies with ectodermal, endodermal, and mesodermal cell types. Further, culture of ES cells to confluence or induction of differentiation with retinoic acid or dimethylsulfoxide results in morphological differentiation into fibroblasts, adipocytes, and epithelial, neuronal, and muscle cells. These ES cells have a normal diploid complement of 38 chromosomes. Scanning electron microscopy of the ES cells reveals a rounded or polygonal, epithelial-like cell with numerous microvilli. The differentiation of these embryonic cell lines into several cell types indicates a pluripotent cell. Furthermore, chimaeric swine have been successfully produced using such ES cells.