Integration site of mutated A-GFP clones. From A2 and A9 clones (Fig. 3), Stu I–digested DNA fragments containing the transgene and adjacent integration sites were isolated and sequenced. Bold lines indicate genomic chicken DNA. Nearby CACCTG motifs in the genomic DNA are indicated. Arrows indicate chicken cDNA sequences and the shaded portions align with the isolated Stu I fragments. Asterisks indicate mutations found in the unsorted A9-1 subclone after 6 wk of culture.