Bmi1gfp

Transgenic mice were Bmi1^CreERT/+ (Ref. 21 (link)), Bmi1^GFP/+ (Ref. 22 (link)), Rosa26^DTA/+ (Ref. 23 (link)), Rosa26^YFP/+, Rosa26^Tomato/+ (Ai9) and β-actin^GFP/+ (all from Jackson Laboratory), all on the C57BL/6 background. The full description of transgenic mouse lines and their application in this study can be consulted in Table I in the online-only Data Supplement. Tamoxifen (Tx) was dissolved in corn oil (Sigma); mice received Tx (i.p.) every 24 h for three consecutive days (225 μg/g body weight daily), or once (7.5 μg/g body weight) for low Tx induction. Since preliminary analysis showed no differences between male and female mice, all experiments were carried out in males and females, as recommended by the US National Institutes of Health.^{24 (link)} Animal studies were approved by the CNB-CSIC Ethics Committee and by the Division of Animal Protection of the Comunidad de Madrid (PA 56/11, PROEX 048/16). All animal procedures conformed to EU Directive 2010/63EU and Recommendation 2007/526/EC regarding the protection of animals used for experimental and other scientific purposes, enforced in Spanish law under Real Decreto 1201/2005.