FIG. 1.

Targeting strategy for mafA mutagenesis and LacZ expression in pancreatic islets in MafA mutant mice. (A) Schematic representation of the wild-type allele, the targeting construct, and the expected product of homologous recombination between them. (B) Southern blot of tail DNA showing NheI-cleaved DNA fragments corresponding to the wild-type (11 kbp) and targeted (16 kbp) mafA alleles. (C) β-Galactosidase expression (blue) in MafA^+/− pancreatic β cells. Immunostaining was performed with antiglucagon (green) and anti-insulin (red) antibodies. Nuclear β-galactosidase staining overlaps that of insulin-expressing cells (merged).