PRODUCTION OF A NEW MONOCLONAL-ANTIBODY RECOGNIZING ALPHA-ACTININ - ANALYSIS OF THE CHANGES IN SUBCELLULAR EXPRESSION IN THE DEVELOPING CHICK HEART

A new monoclonal antibody that recognizes alpha-actinin in cardiac mus cle cells was used in a quantitative study (fluorescence activated cel l sorting and polyacrylamide gel electrophoresis) of the expression of this protein during chick embryo development, to determine the change s in cytoplasmic and cytoskeletal compartments. Alpha-Actinin expressi on was weak in early stages of development (Hamburger and Hamilton sta ge 18) and increased steadily until Hamburger Hamilton stage 40. In al l stages, the protein was more abundant in the cytoplasmic compartment . The monoclonal antibody cross-reacted with alpha-actinin in chicken smooth and striated muscle cells and also showed a faint cross-reactio n with human cardiac muscle alpha-actinin.