Pdx1-tTA/TetO-REST adult mice are diabetic. (A) Representative immunostaining of pancreas from adult bigenic Pdx1-tTA/TetO-REST for PDX1 (red) and REST (green) (left panel) or Glucagon (red), REST (green) and insulin (white) (right panel). Left panel shows partial overlap of REST and PDX1 stainings, indicative of a mosaic expression of REST. Right panel shows Insulin+/REST+ double positive cells, while none of the glucagon+ cells are labeled for REST. Scale bars, 25 μm. (B) Blood glucose measurements in adult animals show hyperglycemia in bigenic Pdx1-tTA/TetO-REST (n = 6), as compared to Pdx1-tTA animals (n = 6). ***p < 0.001 versus values of control littermates.