| Insertion site | Normal karyotype | Dicentric chromosome | Acentric chromosome | >2n | N optical fields |
|---|---|---|---|---|---|
| chr. 7 | 40 | 15 | 73 | 16 | 100 |
| chr. 15 | 40 | 19 | 23 | 19 | 29 |
Cells with inverted loxP targets, inserted on chromosome 7 or chromosome 15, were exposed to Cre protein and scored for dicentric or acentric figures, or polyploidy (>2n), in metaphase. Chromosome-specific paints were used to recognize chromosome 7 or 15