Characterization of a novel C-type lectin cDNA, CLEM 20 cDNA, specifically expressed in mouthparts of the flesh fly Sarcophaga peregrina

摘要

We have characterized a novel gene, CLEM 20, from the flesh fly Sarcophaga peregrina, which shows significant homology to the C-type lectin family. CLEM 20 mRNA was highly transcribed from the second day after eclosion only in the C-type lectin-producing tissue (CLPT) located at the tip of mouthparts. In the CLPT, CLEM 20 mRNA tended to be detected in several cells neighboring the muscle. CLEM 20 protein localized to a specific site in the cytoplasm of several cells in the CLPT. We had already reported that CLEM 36, another C-type lectin of this fly, was expressed in the CLPT and secreted into saliva (Yamamoto-Kihara and Kotani, 2004). CLEM 36 mRNA tended to be detected in several CLPT cells neighboring the opening site of the food canal, and CLEM 36 protein was synthesized abundantly in the cytoplasm and gathered in a specific part of the cytoplasm in the CLPT. Localization of CLEM 20 mRNA and protein in the CLPT seemed to be different from that of CLEM 36 mRNA and protein. Our results indicate that CLEM 20 is a distinct C-type lectin from CLEM 36 and that the localizable difference in the CLPT between CLEM 20 and 36 protein may reflect differences in the secretory process into saliva, such as the secretory rate or the amount of the produced protein.