FIG. 7.

Exogenous CK2β expression in NSC-derived CK2β^−/− embryonic stem (ES) cells promotes proliferation and oligodendroglial differentiation. (A) Clonal selection of CK2β^−/−, Cre-pMSCV-puro-cultured (Cre/puro^R) ES cells expressing exogenous HA-CK2β^wt/Neo^r protein. CK2β^−/wt, Cre/puro^R ES cell clones were generated in parallel and served as positive controls. (B) Western blot analysis with anti-CK2β (left panel) and anti-HA (right panel) antibodies of CK2β^loxP/− ES cells, CK2β^loxP/− and HA-CK2β^wt/Neo^r ES cells, and CK2β^−/−, Cre/puro^R, and HA-CK2β^wt/Neo^r ES cells. Note the complete absence of the endogenous CK2β protein in the CK2β^−/− ES cell extract. (C) Proliferation analysis of NSC-derived ES cells. The ratio (percentage) of the number of cells present in neurosphere-derived CK2β^−/− ES cells expressing the exogenous HA-CK2β^wt protein to the number of cells present in control neurosphere-derived CK2β^−/wt ES cells was unchanged when normalized to the CK2β^−/wt ES cell line (7 differentiation cultures). (D) O4⁺ differentiating OPCs were identified from neurosphere-derived CK2β^−/− ES cells expressing the exogenous HA-CK2β^wt protein and allowed to differentiate. Scale bar, 100 μm.