Fig. 4. Formation of large TIN2 domains is independent of telomeres and TRF proteins. (A) HMECs (strain 184) were cultured as a monolayer on plastic and growth-arrested before fixation and dual staining for TIN2 (red) and telomeres (PNA FISH; green) (upper panels), TIN2 (red) and TRF1 (green) (middle panels), and TIN2 (red) and TRF2 (green) (lower panels). (B) Higher magnification images of dual staining for TIN2 (red) and TRF2 (green) showing colocalization at small foci (yellow), indicating telomeric localization. Nuclei were counterstained with DAPI (blue). Arrowheads indicate large TIN2 domains. Bar, 5 µm.