Figure 1
Number and brightness analysis of HP1 alpha oligomerization.
(A) Intensity image of a NIH3T3 nucleus expressing free EGFP with the DNA stained by Hoechst 33342. (B) Region of interest from (A) selected for brightness analysis in the EGFP channel. (C) Region of interest in (B) pseudo-colored according to the brightness distribution of free EGFP in (D). As can be seen free EGFP only exists as a monomer throughout the nucleus. (E) Intensity image of a NIH3T3 nucleus expressing HP1-α-EGFP with the DNA stained by Hoechst 33342. (F) Region of interest from (E) selected for brightness analysis in the HP1-α-EGFP channel. (G) Region of interest in (F) pseudo-colored according to the brightness distribution of HP1α in (H). As can be seen dimers are located around the periphery of the heterochromatin foci. (I) Intensity image of a NIH3T3 nucleus expressing HP1-α-I165E-EGFP with the DNA stained by Hoechst 33342. (J) Region of interest from (I) selected for brightness analysis in the HP1-α-I165E-EGFP channel. (K) Region of interest in (J) pseudo-colored according to the brightness distribution of HP1-α-I165E-EGFP in (L). As can be seen HP1-α-I165E-EGFP is monomeric throughout the nucleus even at the periphery of heterochromatin foci. (M) Intensity image of a NIH3T3 nucleus expressing free H2B-EGFP with the DNA stained by Hoechst 33342. (N) Region of interest from (M) selected for brightness analysis in the H2B-EGFP channel. (O) Region of interest in (N) pseudo-colored according to the brightness distribution of H2B in (P). As can be seen H2B is monomeric throughout the nucleus even at the periphery of heterochromatin foci.
