DYSTROPHIN CLEAVAGE AND SARCOLEMMA DETACHMENT ARE EARLY POST-MORTEM CHANGES ON PASS (DICENTRARCHUS-LABRAX) WHITE MUSCLE

Using specific dystrophin antibodies directed against a conserved C-te rminal sequence, we demonstrated that dystrophin of fish white muscle was quickly degraded by 50% within 24h and by 100% within 2 days, in p arallel with titin cleavage and alpha-actinin release from Z-disks. Th ese changes were accompanied by sarcolemma detachment from the myofibe rs in costameres (the structures containing dystrophin) and Z-disks we akening. For muscle stored during 2 to 6 mo before thawing, total dyst rophin disappearance was observed at 4 degrees C in <8h. Dystrophin ma y serve as a marker for stored fish to evaluate post mortem changes or detect a thawing-freezing process.