Cloning of an aquaporin-like cDNA and in situ hybridization in adults of the mosquito Aedes aegypti (Diptera : Culicidae)

A cDNA encoding a putative water channel protein, aquaporin, was cloned fro m a cDNA library of Aedes aegypti Malpighian tubules. The cDNA encodes a 26 .11 kDa protein similar to insect aquaporins from Haematobia irritans exigu a (Diptera) and Cicadella viridis (Homoptera), and to mammalian aquaporin 4 . Localization of the messenger RNA (mRNA) was performed by in situ hybridi zation of Malpighian tubules and analysed by fluorescence and confocal micr oscopy. The mRNA was localized in tracheolar cells associated with the Malp ighian tubules. No signal was detected in the Malpighian tubule epithelium. The molecular mechanisms for water movement between tissues and tracheoles are not yet elucidated in insects. Our results suggest a model to explain fluid movements in tracheoles during insect respiration.