Evidence for continued tamoxifen-independent recombination with age in R/−; CreERt2 mice.

The table shows the total number of uninjected and carrier-only injected R/−; CreERt2 mice analyzed within each age group, for male and female mice. Uninjected and carrier-injected R/−; CreERt2 with equivalent or fewer cells in the DP gate to R/− controls were considered not to have undergone tamoxifen-independent Cre-mediated recombination. When the results for males and females are combined, the proportion of mice showing evidence of tamoxifen-independent Cre-mediated recombination varies significantly with age and there is a trend for this to increase with age. *p-value was calculated to compare the recombination frequencies among the four ages by 2×4 Fisher's Exact test.Evidence for continued tamoxifen-independent recombination with age in R/−; CreERt2 mice.