Neonatal cardiomyocytes expressing various α-actinin–YC-Nanos fused into the Z disks in cardiomyocytes. From left to right: α-actinin-YC-Nano15, α-actinin–YC-Nano50, α-actinin–YC-Nano65, and α-actinin–YC-Nano140. Epifluorescence observation. Top, Venus fluorescence (yellow); bottom, ECFP fluorescence (cyan). Note the lack of F.I. changes for Venus or ECFP upon change in the state of the myocyte (i.e., from relaxation to contraction and vice versa) in the α-actinin–YC-Nano15– or α-actinin–YC-Nano50–expressing myocyte. Objective lens, 60×. Video speed, 33 fps. Bar, 10 µm. See Fig. 2 for details.
