Identification of myosin heavy chain isoforms in skeletal muscle of four Southern African wild ruminants

Abstract

The aim was to separate and characterize the myosin heavy chain (MHC) isoforms of four southern African wild ruminants, namely Blesbuck ( Damaliscus dorcas phillipsi), Kudu ( Tragelaphus strepsiceros), Black Wildebeest ( Connochaetes gnou) and Blue Wildebeest ( Connochaetes taurinus). Longissimus dorsi muscle samples were subjected to SDS-PAGE and Western blot analyses using antibodies raised against MHC isoforms. The specificity of these antibodies was assessed using immunohistochemistry combined with ATPase histochemistry, Three MHC isoforms were separated and the bands were identified from fastest to slowest migrating as MHC I, MHC IIx and MHC IIa. The mobility of the MHC isoforms was similar for all four species, including that of bovine, but differed from human muscle. Kudu muscle exhibited the lowest proportion of MHC I and the highest proportion of MHC IIx, whereas Blesbuck muscle had the least MHC IIx. The two Wildebeest species were intermediate in isoform content. In conclusion, when new species are studied, existing electrophoretic protocols may need to be modified to achieve quantifiable separation and isoform migration pattern must be verified in order to reach correct interpretations. Furthermore, antibody specificity may differ between techniques as well as species and needs confirmation.