Dystrophin-associated proteins in obliquely striated muscle of the leech Pontobdella muricata (Annelida, hirudinea)

The distribution of dystrophin-associated proteins (beta -dystroglycan, alp ha -, beta-, gamma- and delta -sarcoglycan, alpha -syntrophin and sarcospan ) were studied in obliquely striated muscle of the leech Pontobdella murica ta. Western blot analysis and immunohistochemical electron microscopy, usin g various polyclonal antibodies, were employed. Western blot analysis of al l of these antibodies showed a single band, with approximately the same mol ecular weights as similar proteins detected in vertebrate muscles. The immu noelectron microscopy study confirmed specific immunogold labelling in the membrane of muscle cells. Since all dystrophin complex components have simi lar molecular weights and the same localisation in leech as in vertebrate s keletal muscle, we assume that these proteins have similar properties in le ech and vertebrate muscle. The presence of these molecules in annelid muscl es, together with a short version of dystrophin (previously described as ID Lp-140) is of particular interest since phylogenetic and functional studies on this material could help to shed new light on the role and function of this complex in the muscle membrane.