Identification of a Novel Secretory Gland Producing C-type Lectin in the Flesh Fly (Sarcophaga peregrina), and its Characterization

C-type lectin-producing tissue, designated as CLPT, constitutes mouthparts of the flesh fly (Sarcophaga peregrina) and produces a C-type lectin, CLEM 36, which is found to be secreted into saliva. In the present study, CLPT was investigated by immunohistochemical method using a transmission electron microscope (TEM) and scanning electron microscope (SEM), in order to clarify the secretion pathway of CLEM 36. CLPT was found to consist of cells having a microvillus. Each CLPT cell was connected to a fine duct. The fine ducts were bundled together and connected to the food canal. CLEM 36 was densely detected in the microvilli of CLPT cells, and also detected in cytoplasm, and ducts of CLPT. CLPT was found not to be connected to the salivary glands. Since little expression of CLEM genes including CLEM 36 was detected in the thorax and abdomen including the salivary glands in our previous study, when taken together, our current findings suggest that CLPT is a novel secretory gland which is independent of salivary glands, and has its own role in the intake of foods.