Development and ultrastructural changes of sarcosomes during honey bee flight muscle development

Abstract

The indirect flight muscle of the honey bee forms by the accumulation of myoblasts into a syncytium. Incorporation of myoblasts into the muscle fiber continues during much of the pupal period. The mitochondria of the honey bee flight muscles have the following structure during developmental stages: Myoblast mitochondria are ovoid and are incorporated in the muscle fiber along with the cytoplasm. The early pupal stage muscle fiber contains ovoid and filamentous mitochondria. The middle pupal muscle fiber contains filamentous, ovoid and vesicular mitochondria with few internal tubules. The late pupal stage muscle contains only ovoid mitochondria containing granules and some internal tubules. The newly emerged honey bee muscle contains ovoid mitochondria containing many internal tubules and a few granules. The mature honey bee muscle contains large ovoid mitochondria (sarcosomes) packed with internal tubules. Flight muscles sarcosomes increase in size and show a twelvefold increase in volume from late pupal period to adult maturation. Correlation of sarcosome ultrastructure and cytochrome changes is carried out.