Figure 8

Relation of excision and Cre expression level. The northern blot X-ray film of Figure 6b was subjected to densitometry; the average of band intensities of samples from the 1st, 7th, and 11th passages were calculated; and the relative band intensity to 71/JTX-P-Cre 4, which showed the lowest expression, was calculated and plotted on the x-axis. The highest value of the excised allele rate calculated in Figure 7c was plotted on the y-axis. In 71/66-P-Cre clones, the recombination rate was apparently higher than in other clones.