Fig. 2

Rescue with mutated mouse Sox2 proteins. a Amino acid alignments of HMG-box from mouse Sox family members. Amino acids conserved in all Sox factors are marked with blue, and amino acids unique to SoxB1 are highlighted in red. b Reporter gene assays of mutant proteins. The position and identity of amino acid substitutions in each line are shown on the left: all proteins show comparable ability to activate the Sox2 reporter. Each assay represents the mean of 3 replicates, error bars mean standard deviations. c Rescue ability of altered Sox2 proteins. The numbers of primary colonies and standard deviation obtained with each mutant Sox2 protein are indicated under the ID. Colums represent: 1 – primary transfectants in the absence of Tc. 2 – Secondary colonies in the presence of Tc. 3 – Colonies at passage 3 in the presence of Tc. Only the M8 (K57E) mutant failed to provide wild-type Sox2 function. d Immunostaining of rescued ES cells. Rescued ES cells at passage 4 in the presence of Tc were stained for Sox2, Oct3/4, Nanog and Klf4. Mutant forms of Sox2 were detected by a goat polyclonal anti-Sox2 antibody