<i>Arx</i> inactivation in glucagon-producing cells results in the misallocation of non-β-cells within the islet.

Representative photographs of immunohistochemical analyses performed on sections of 6 month-old controls (A, D, G, J, M), 6 month-old Glu-ArxKO (B, E, H, K, N) and 6 month-old 4mDox+ IndGlu-ArxKO (C, F, I, L, O) pancreata using the indicated antibody combinations. Both Glu-ArKO and Dox+ IndGlu-ArxKO animals displayed increased insulin+ cell contents compared to controls, these cells being negative for glucagon (A–C, J–L), somatostatin (D–F, J–O) and PP (G–I, M–O). Interestingly, unlike in controls where non-β-cells were distributed within the islet mantle zone (J, M), these were found preferentially located at a pole of the islet, adjacent to neighboring ducts in mutants (K–L, N–O). For the purpose of clarity, in selected photographs, the ductal lumens are outlined in yellow and islets in dashed white lines.