The sequence for icre was inserted into a BAC (RP23-343C17) by recombineering techniques, replacing the sequence between the start codon in exon 2 of the Gcg (glucagon; proglucagon) locus and the stop codon in exon 6. The modified BAC was purified and injected into fertilized oocytes. Four founder lines were established initially and copy numbers were determined (line: 01, 7-8 copies; 12, 2-3; 14, 1; 30, 1). Line 12 was analyzed in detail in the publication. (J:186436)