Two models of transgenic mice. 1A and 1B: Scheme of DNA constructs for the generation of two distinct transgenic mouse models, in which the α-MHC-Promoter (α-MHC-Pr.) drives the transgene expression in the postnatal heart. 1A. DNA construct for the generation of cardiac-specific overexpression of SRF transgenic (SRF-Tg) mice. 1B. DNA construct for the generation of cardiac-specific antisense-SRF transgenic (Anti-SRF-Tg) mice. 1C. Western blot revealed increased SRF protein in SRF-Tg versus wild-type (WT) mice, and decreased SRF protein level in Anti-SRF-Tg versus WT mice. 1D. Northern blot analysis of cardiac gene expression in wild-type (WT) versus SRF-Tg, as well as WT versus Anti-SRF-Tg (Anti-SRF) mice. The SRF transcript (SRF*) was detected by a 32P-labelled double-strand SRF cDNA fragment, which hybridizes with both sense-SRF transcript and antisense-SRF transcript, respectively. The probes for ANF, β-MHC, cardiac actin, MLC2v and SERCA2 are 32P-labeled oligonucleotides.