FIG. 5.
Histological examination of cardiac tissues of heart-specific Txnrd1 KO mice. (A) Semiquantitative RT-PCRs revealed reduced levels of Txnrd1 transcripts in the hearts of heart-specific Txnrd1 KO mice (loxP/− Cre+) compared to those in the hearts of control animals (loxP/− Cre−). Note that Txnrd1 mRNA levels were comparable in other tissues, such as the kidneys, showing the specificity of the MLC2a-Cre line. In the bottom panels, immunoblotting reveals the high efficacy of deletion of the targeted Txnrd1 allele in the hearts of Txnrd1loxP/− Mlc2a-Cre mice, but not in the kidneys. Provided that the antibody used was highly specific, the faint band migrating at the position of Txnrd1 was most likely due to cell and tissue heterogeneity within the heart and to an incomplete deletion of the targeted allele by Cre recombinase in vivo. Serial sections of control (B and D) and Txnrd1-deficient (C and E) hearts show no differences in nuclear and cellular morphology between WT and KO cells by hematoxylin and eosin staining (B and C) and phase-contrast imaging (D and E) of cardiomyocytes. Bars = 25 μm (B and C) and 20 μm (D and E).