Histological analysis of TAT-MafA-treated pancreata in neonate pups.

(A) Representative section of a control pancreas (in utero injection: vehicle), showing a disorganized pattern of β cell expression (red) in islets. (B) Representative section of a pancreas of a neonate pup treated in utero with TAT-MafA. Islets are larger, rounder and more organized than in controls. Size bars: 500 µm. (C–D) High magnification confocal microphotograph of control neonatal (C) and TAT-MafA-treated (D) pancreata. While the former exhibits small islets in the process of coalescence, islets from the latter are already larger in size. Prohormone convertase (PC) 1/3 staining (green) was similar in both samples despite a trend in favor of the experimental group by qRT-PCR (fig. 4). Glucagon staining (purple) was stronger in (D) at the same exposure. Size bars: 75 µm. (E) Glut-2 staining (green) is not evident in control samples, but can be observed in TAT-MafA samples (F). Size bars: 75 µm.