A, L1 transcripts are elevated in several tissues of SIRT6 KO mice. Organs were harvested from 27 days old WT and SIRT6 KO mice. L1 mRNA was assayed via qRT-PCR and normalized to actin and WT heart was used as a reference.
B, Western blot analysis of L1 ORF1p . Both WT and KO MEFs, as well as sample young (4 month; black bars) and old (24 month; while bars) WT mouse tissue, were subjected to Western blot analysis. KO cells and old WT tissue both displayed significantly elevated ORF1p staining (p < 0.001, t-test). The mouse LINE-1 ORF1p antibody (EA13 Rb Monoclonal) was developed and validated in the lab of J.D. Boeke by transfection experiments and peptide blocking.
C, Immunostaining of young (5 month) and old (25 month) fixed liver tissue. Tissue samples were stained using LINE1 ORF1p (EA13). Cells were scored for positive signal and counted. n=3 animals per age group. p < 0.001, t-test
D, NRTI treatment reduces L1 DNA content in SIRT6 KO mice.
E, L1 DNA content in NRTI treated WT mouse tissues. L1 DNA content was assayed at 27 days old and normalized to 5S rRNA gene. Four animals were assayed for each treatment and error bars indicate s.d. Significance was determined by t-test and asterisks indicate p < 0.05.