Fig. 2

Nuclear DUX4 PLA signals in an FSHD1 biopsy (microscope fields 1–3). Sections of biceps muscle obtained from a FSHD1 donor were processed for two primary antibody PLA and nuclei were stained with bisbenzimide. As indicated, each row includes images of a single field showing the DUX4 PLA signal (red), nuclei (blue), and merged PLA and nuclei signals. For field 1, row A shows a single nucleus with a positive PLA signal (red), as well as one nearby nucleus that was unstained; and Row B shows the positive nucleus at higher magnification. For field 2, row C shows one nucleus with a positive PLA signal amid several nearby unstained nuclei; and row D shows the positive nucleus at higher magnification. For field 3, row E shows an additional example of a nucleus with a positive PLA signal with three nearby unstained nuclei; and row F shows the positive signal at higher magnification. Bar in A 1 = 10 µm for row A. Bar in B1 = 4 µm for row B. Bar in C1 = 10 µm for row C. Bar in D 1 = 4 µm for row D. Bar in E 1 = 10 µm for row E. Bar in F.1 = 3.3 µm for row F