H3.1 is minimally mobilized in U2OS cells.

(A) Average normalized levels of free GFP-H3.1 relative to mock-infected cells at 4 or 7 hpi, respectively. U2OS cells were transfected with plasmids expressing GFP-H3.1. Transfected cells were mock-infected or infected with 30 PFU/cell of strain KM110 (KM110) or 6 PFU/cell of strain KOS (KOS). Mobilization of GFP-H3.1 was examined from 4 to 5 (4) or 7 to 8 (7) hpi by FRAP; error bars, SEM; dashed line, average normalized levels of free GFP-H3.1 in mock-infected cells. (B) Frequency distribution plots of the percentage of free GFP-H3.1 per individual cell at 4 or 7 hpi; dotted line, one SD above the average level of free GFP-H3.1 in mock-infected cells. (C) Average initial rates of normalized fluorescence recovery relative to mock-infected cells at 4 hpi; error bars, SEM. (D) Frequency distribution plots of the initial rate of normalized fluorescence recovery of GFP-H3.1 per individual cell; dotted line, one SD above (KM110) or below (KOS) the average initial rate of normalized fluorescence recovery in mock-infected cells. **, Pn.s., not significant.