(A) Targeting strategy for the Tip60 locus. Tip60 wildtype allele, targeting vector, targeted allele, floxed allele after removal of the PGK-Neo cassette, and the mutant Tip60 allele created by Cre-mediated recombination are shown. LoxP (black triangle) and FRT (open triangle) sites are marked. The arrows indicate the position of diagnostic primers P1-P3 (see Supplementary file 1). (B) PCR genotyping of Tip60 alleles. The wildtype allele produces a 331 bp amplicon (primers P1, (P2) while the floxed allele produces a 429 bp amplicon (P1, P2). Deletion of the LoxP-flanked region of the Tip60 locus leads to a 487 bp fragment (P1, P3). (C) TUNEL immunoreactivity on brain sections of Syt10Cre/+Tip60+/+ (control), arrhythmic Syt10Cre/+Tip60 fl/- animals, and Syt10Cre/+Tip60 fl/- sections treated in situ with DNase I. (D) mRNA expression of housekeeping genes in Tip60fl/- MEFs transduced with either AdGFP or AdCre, 24 hr after Dex synchronization. Data are mean ± SD (n = 3; ns > 0.05 and ***p<0.001, Student’s t-test). (E) Flow cytometric analysis of AdGFP, AdCre transduced, and heat-treated (3 min, 95°C) confluent Tip60fl/- MEFs. (F) Bioluminescence tracing of Dex-synchronized Bmal1-LUC MEFs transduced with AdGFP (black) or AdCre (red) (n = 4).