Comprehensive identification of <i>Krüppel-like factor</i> (<i>Klf</i>) family members whose overexpression achieves leukemia inhibitory factor (LIF)-independent self-renewal of mouse embryonic stem (ES) cells.

<p>(A) A schematic representation of Klfs. These proteins have highly homologous C-terminal DNA binding domains characterized by three C₂H₂ zinc finger motifs, shown in green boxes. The number of amino acids is shown to the left. (B) Western blot of proteins from mouse ES cells overexpressing FLAG-HA epitope-tagged Klf. Anti-HA and anti-β-actin antibodies were used to detect HA-tagged Klf and endogenous β-actin, respectively. Arrowheads indicate HA-tagged Klf proteins. (C) A schematic illustration of the experimental outline to assay the ability of a Klf protein to maintain self-renewal. (D) Generation of colonies from ES cells carrying either the empty vector or a Klf expression vector in the presence or absence of LIF. Scale bar: 2 mm. (E) The percentage of AP-positive colonies. Asterisks indicate statistical significance. *<i>P</i> < 0.05; **<i>P</i> < 0.01.