Investigation the effects of autophagy inhibitor chloroquine in posterior silk gland of silkworm Bombyx mori, during larval-pupal metamorphosis.

Remodeling or completely elimination of larvae-specific tissues and organs in holometabolous insects occur with programmed cell death during larval-pupal metamorphosis. The degeneration of the posterior silk gland, which is a larval-specific tissue in the silkworm, Bombyx mori, occurs with interaction of autophagy and apoptosis mechanisms due to an increase in the level of ecdysteroid in the hemolymph. Studies in the posterior silk gland showed that, while autophagic cell death occurs during prepupal stage, apoptosis is observed in the early phase of pupa stage. In this study, the role of autophagy in silkworm, Bombyx mori posterior silk gland was investigated during larval-pupal metamorphosis. For this purpose, two different doses of chloroquine which is an autophagy inhibitor, was applied during the day 7 and 8 of the fifth larval stage and then its effects on posterior silk gland was examined. The total protein amounts of the posterior silk gland were determined by Bradford protein assay and the activities of the lysosomal enzyme acid phosphatase was detected. The posterior silk gland tissue sections which were stained with hematoxylin eosin were observed under light microscope and, morphological changes in the posterior silk gland during larval-pupal metamorphosis were shown.