Figure 6: Insulin (green), glucagon (red) and SOX17 (blue) expression during the first and second trimester of human fetal development (1- 24 wpc), as demonstrated by samples 8.4, 10.6, 12.1, 15, 17, and 20 wpc. In the first trimester, SOX17 expressing cells are scattered non-specifically amongst the insulin and glucagon expressing cells. Upon islet-like cluster formation at 10.6 wpc SOX17 expressing cells are also found in the islet-like clusters. SOX17 is not co-expressed in glucagon expressing cells, however select insulin expressing cells appear to co-express SOX17. In the second trimester, SOX17 expressing cells are spatially associated with glucagon expressing cells within the islet structures. At 15, 17, and 20 wpc SOX17 is not coexpressed in insulin or glucagon expressing cells. Areas surrounded by a box are shown at higher magnification (inset). Scale bars are 50 and 10 μM respectively.