Fig. 2

Inducible transgenic strains modulate miR-133 expression in vivo. A) Transgenic constructs for inducible overexpression (Tg(miR-133a1)^pd47; top) or reduction of miR-133 (Tg(miR-133sp)^pd48; bottom). B) Northern blot analyses demonstrating elevated miR-133 levels in Tg(miR-133a1)^pd47 ventricles, and miR-133 depletion in Tg(miR-133sp)^pd48 samples, following heat induction (uninjured, left; 7 dpa, right). No differences were detected in mature miR-21 and miR-1 levels among wildtype, Tg(miR-133a1)^pd47 and Tg(miR-133sp)^pd48 samples. 5s rRNA was used as a control for Northern blot studies. C–E) In situ hybridizations reveal levels of miR-133 remain elevated in Tg(miR-133a1)^pd47 and diminished in Tg(miR-133sp)^pd48 24 h after the completion of heat-treatment, when compared to heat-treated wildtype controls. F) Real-time QPCR studies document miR-133 levels are significantly elevated in Tg(miR-133a1)^pd47 and depleted in Tg(miR-133sp)^pd48 heart samples. Expression of miR-24, miR-29, miR-144, miR-181 and miR-182 is unaltered under conditions of miR-133 modulation. Student′s t-test p-value < 0.05 for * and **. (sp, sponge; dpa, days post-amputation). Scale bar in (C–E) represents 100 μm.