The fine structure and mechanism of breakdown of larval intersegmental muscles in the blowfly Calliphora erythrocephala

摘要: The intersegmental muscles of Calliphora are composed an array thick and thin myofilaments, in which average ten myofilaments surrounds each myofilament. Z-disks perforated, both pass through the perforations when muscle is fully contracted. During puparium formation contract only partially, so as to bring ends into contact with, but not penetrate, Z-disk. It shown that invasion by phagocytes under humoral control, can be prematurely or artificially induced injection crustecdysone. A change haemocyte population crustecdysone first morphological indication onset metamorphosis. Breakdown mediated nervous stimuli. signal inviting haemocytes individual unknown, changes doomed precede invasion. Attenuated folds plasma membrane penetrate possess normal contractile elements. Adjacent unite, isolating fragments within cytoplasm. Soluble colloidal elements taken coated vesicles, line pockets haemolymph between muscle. Coated vesicles circulating capable non-proteinaceous substances such thorium dioxide, transporting them cell, where they accumulate vacuoles. Within phagocytic degraded a well-developed vacuolar apparatus. Acid phosphatase activity demonstrated many vacuoles. The catabolic process apparatus leads accumulation lipid glycogen reserves. Protein protein+RNA vacuoles also accumulate, extent degradation macromolecules unknown. Rupture eventual release all modified components haemolymph.