Fig. 3. (A) Western blot on muscle homogenates enriched in myofibrillar proteins from infected (i) and healthy (h) individuals, probed with a monoclonal antibody to Drosophila MHC. Lanes contain identical protein concentrations. Aside from the 206 kDa muscle MHC and non-specific reactivity to some high-molecular-mass proteins, a 165 and 155 kDa protein were identified. Left tick marks represent molecular mass standards (lane not shown). The presence of 165 and 155 kDa bands in infected muscle indicates that this may be a relatively `high-powered' infected individual, as shown in Fig. 5E. However, no performance measures were obtained from this individual's muscles. (B) Silver-stained SDS-PAGE gel showing peptides obtained by calpain (lane b) digestion of purified L. pulchella MHC from both healthy and infected individuals (lane a). In calpain-treated samples, a 156 kDa peptide can be observed, as well as a 122 and 110 kDa peptide. In addition, we putatively identified a calpain 80 kDa subunit, and other bands as calpain autodegradation products [i.e. similar to results reported by Pemrick and Grebenau (Pemrick and Grebenau, 1984)].