Figure 1
ESC-like iPSC were derived from six diverse inbred mouse strains. (A–F) The iPSC are three-dimensional dome shaped colonies that were expanded as single cells using trypsin and grown on a gelatin coated tissue culture plate. Slight differences in colony morphology were observed on gelatin. (G) Genetic background affected the number of iPSC derived. 129S1/SvImJ, C57BL/6J, and CAST/EiJ backgrounds produced the most iPSC. A total of 6 × 105 fibroblasts were reprogrammed for each strain, with the total number of initial iPSC-like colonies subcloned from the reprogramming noted for each strain. (H,I) NOD/ShiLtJ and WSB/EiJ iPSC emerged as a flattened colony on the same plane as the surrounding MEF. (J,K) Selected NOD/ShiLtJ and WSB/EiJ iPSC were passaged manually or with collagenase type IV. The colonies retained a flattened morphology and could not be expanded even as cell clumps. All colonies showed signs of differentiation (brown color) and died within several passages. Scale bars represent 200 μm.
