Fig. 2.

Generation of Ins2^Apple/+ mice. A: schematic of the Ins2.Apple.hGH exchange vector, which contains a Lox71 site, the histone 2B (H2B)-Apple sequence, a 3-kb fragment of human growth hormone (hGH), an FRT-flanked pgk-Hygro selection marker, and a Lox2272 site. The Ins2^Apple+Hygro allele was generated by recombinase-mediated cassette exchange (RMCE) in mouse embryonic stem cells expressing the Ins2^Apple.LCA allele. To generate the final Ins2^Apple allele, mice with the Ins2^Apple+Hygro allele were interbred with animals that express FLPe to excise the pgk-Hygro cassette. Primer binding sites are represented by arrows above the schemes. B: PCR analysis used to identify mice expressing the targeted allele and mice in which pgk-Hygro^R resistance cassette has been excised. C: representative images from frozen pancreatic sections from Ins2^Apple/+ mice subjected to immunofluorescence using antibodies against insulin (Ins), glucagon (Gcg), somatostatin (Sst), pancreatic polypeptide (PP), and Apple. Scale bar = 50 μm. PU-TK, puromycin resistance-Δ-thymidine kinase.