Time-course study of the relative quantities of tropomyosin expression by immunofluorescence staining in RNA-treated (7 ng/μl of microRNA499c) axolotl hearts. A. The immunofluorescent images show mutant hearts that were fixed and stained for tropomyosin after incubation with 7 ng/μl of microRNA499c for 0, 1, 2, 3, 4 and 5 days; the 0- control was without treatment. B. The average levels of fluorescence were quantified with ImageJ software as a percentage of that expressed in normal hearts, which was set to 100%. Significance (*p-value) between treated on the second day following days hearts and untreated hearts is p < 0.05, n=3.