Autophagic and lysosomal markers localize to RVs in IBMPFD tissue. (A) Immunofluorescence images of quadriceps muscle using p62 and Lamp1 or -2 antibodies. Quadriceps section from a 9-mo-old VCP-WT mouse, age-matched VCP-RH transgenic, 12-mo-old VCP-RH transgenic, and IBMPFD patient muscle biopsy are shown. Open arrows highlight p62 and Lamp1/2 colocalization, and closed arrows show regions of only p62 immunofluorescence. Single myofibers containing RVs are outlined in the merge panels. (B and C) Transmission electron microscopy of tibialis anterior muscle from one of two independent lines (B shows RH12, and C shows RH9 lines) of 12-mo-old VCP-RH–expressing transgenic mice. Note the large vacuolated structures that are perinuclear or subsarcolemmal. Bars: (A) 30 µm; (B and C) 500 nm.