Expression of PREP1, PBX1 and Processing of Somatostatin in ARX ko hESCs.

(A—D) Immunostaining of PREP1, PBX1a/1b, PC1/3, PC2 (all green), somatostatin (red), and insulin (blue) in 26 day differentiated wild type (WT) and ARX knockout (ARX ko) cells, and adult human pancreatic tissue. RT-qPCR of day 17 and day 26 whole population samples examining the expression of transcription factors believed to be involved expression and processing of somatostatin. Wild type (WT; black bars) and ARX ko clone 1 (ARX ko; red bars) cell samples relative to adult human islets expression levels. † indicates p < 0.05 within the genotype over time, * indicates p < 0.05 wild type vs ARX ko at given culture day, N = 4 per group. (E and F) Immunostaining of 13 week human fetal pancreatic tissue for expression of PC1/3 and PC2 (both green), somatostatin (red), and insulin (blue). DAPI is white in all images. Inset is a ~3x enlarged portion from the region indicated by the star. Scale bar is 100 μm for all panels.