Fig. 5: Salhel POU cannot induce pluripotency and is unable to bind octamer DNA.
From: The emergence of Sox and POU transcription factors predates the origins of animal stem cells
a Phylogenetic tree of holozoan homeodomains with a focus on POU branches. b Sequence logos of signature amino acids representing the bipartite POU domain of mouse and unicellular POU sequences. Residues reported to be relevant to DNA binding are boxed60. c Binding of the POU of mOct4 and Salhel to consensus Octamer DNA (n = 3 independent experiments). d Energy logos derived from Spec-seq using a set of sequences with one nucleotide difference to the consensus Octamer motif (ATGCTAAT). e Correlation scatter plots of the relative binding affinities of mOct4 versus Salhel POU for all 705 sequences tested. R = Pearson’s correlation coefficient. The color indicates the residual score from the correlation line. f Top enriched motifs from high throughput-SELEX (3rd Cycle) for mOct4 and Salhel POU. g Whole well scan and representative microscopy images of generated iPSCs with activated GFP expression on reprogramming day 14. Scale bar, 80 μm. h Quantification of iPSC reprogramming efficiency of choanoflagellate POU factors normalized to the colony numbers of mOct4 on day 14 (n = 6, 3 biological replicates each with 2 technical replicates). The box displays the interquartile range, with the left edge representing the lower quartile (25th percentile) and the right edge indicating the upper quartile (75th percentile). The median value is shown as a line splitting the box. Source data and statistics are provided as a Source Data file.
