Induction of the differentiation of lentoids from primate embryonic stem cells

PURPOSE. To produce lens cells from primate embryonic stem (ES) cells in a reproducible, controlled manner. METHODS. Cynomologus monkey ES cells were induced to differentiate by stromal cell-derived inducing activity (SDIA). The lentoids produced by this treatment were processed for immunohistochemical and immunoblotting analysis. The effect of varying the concentration of fibroblast growth factor (FGF)-2 and the density of the ES colonies plated during the differentiation process were also examined. RESULTS. After a 2- to 3-week induction period, lentoids were produced by a subpopulation of ES colonies. Western blot analysis and immunohistochemistry revealed that these lentoids expressed alphaA-crystallin and Pax6. The number of lentoids resulting from treatment increased with increasing FGF-2 concentration and plated colony density. CONCLUSIONS. The differentiation of primate ES cells into lentoids can be achieved by treatment with SIDA. ES cells can be used to facilitate a greater understanding of the mechanisms functioning in differentiation in vivo and in vitro.