Figure 1

Tamoxifen-induced CreERT2 activation in pups affects gain weight and hematopoietic organs. (a) Experimental design for Cre ERT2 activation with tamoxifen injection. Litters are composed of WT and R26CreERT2 animals. Tamoxifen was injected IP at 75 mg/kg for 3 consecutive days from P9 to P11 and animals were euthanized at P19 or P20. (b) Weight curves of WT (n = 17) and R26CreERT2 (n = 27). Values are expressed as a percentage of weight gain compared to the weight at P9 (first tamoxifen injection). Two-way ANOVA with multiple comparisons was carried out to analyze differences in weight gain. (c) Representative images of femurs, spleens and thymus. 3 animals for each group are represented. Scale bar 1 cm. (d) Measurements of bone marrow cell count from two tibias and 2 femurs per animal, femur length, thymus weight, spleen weight, and number of cells per spleen (n = 4–11 mice per group). Mann–Whitney tests were used to assess statistical significance between two groups in these bar graphs. *p-value ≤ 0.05; **p-value ≤ 0.01; ***p-value ≤ 0.001; ****p-value ≤ 0.0001. Data are expressed as mean ± SEM of WT (red circle) and R26CreERT2 (blue inverted triangle) pups.