Fig. 1

CRISPR imaging of telomeres in dCas9-EGFP knock-in mice. a Schematic diagram of dCas9-EGFP Rosa26 targeting vector. b Labeling of telomeres in hepatocytes of dCas9-EGFP mice. TagBFP-TRF1 was used as control. c Quantification of telomere labeling specificity based on co-localization with TagBFP-TRF1 (left panel). Histograms of telomere foci formation efficiency represented by foci numbers in individual nucleus (right panel). The data were collected from at least two mice for each treatment. d Representative images of telomere aggregations observed in dCas9-EGFP mice injected with empty gRNA, gRNAs targeting TRF1, and TRF1 gRNAs plus human TRF1 expression cassette. Aggregation is marked by a red arrow. e Quantification of telomere aggregations in dCas9-EGFP mice injected with different constructs. A two-sided t test was used for statistical comparison. The data were collected from at least three mice for each treatment. f The average MSD curves of telomere in dCas9-EGFP mice injected with different constructs. For the empty gRNA group, 1033 foci were collected in 85 cells from three mice. For TRF1 gRNA group, 1068 foci were collected in 98 cells from four mice. For TRF1 gRNA+TRF1 group, 808 foci were collected in 68 cells from four mice. The data are displayed as mean ± SE