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Characterization of Aquaporin Expression and Function in the Malpighian Tubules of the Larval Mosquito, Aedes aegypti
Author(s) -
Misyura Lidiya,
Donini Andrew
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.889.8
Subject(s) - malpighian tubule system , aedes aegypti , hemolymph , transcellular , paracellular transport , osmoregulation , biology , aquaporin , water transport , microbiology and biotechnology , aedes , gene knockdown , biophysics , larva , biochemistry , ecology , midgut , water flow , salinity , apoptosis , membrane , environmental engineering , engineering , permeability (electromagnetism)
The mosquito, Aedes aegypti , is the primary vector for the arboviral diseases Zika, dengue fever, chikungunya, and yellow fever that affect millions of people worldwide. The larvae of A. aegypti reside in hypo‐osmotic freshwater habitats, where they face dilution of bodily fluids due to the influx of water. The Malpighian tubules (MTs) are one of the major contributors to osmoregulation, whereby, they function in concert with the rectum, to remove excess water from the hemolymph, thus maintaining ionic homeostasis. The epithelium of the Malpighian tubules actively transports ions from the hemolymph into the lumen which creates an osmotic gradient that drives paracellular and transcellular water movement in the same direction. Our previous study has shown that this transcellular water transport occurs through at least one of the six aquaporins (AQP) that A. aegypti possesses, AQP5. In the present study, the function of other AQPs with high relative mRNA abundance in the MTs were studied with the aid of double stranded RNA knockdown. The MT fluid secretion rate and ionic composition of secreted fluid were assessed using Ramsay assay and ion selective microelectrode (ISME), respectively. Hemolymph ion concentrations and larval survival were measured to gauge effects of AQP knockdown on osmoregulation in the larvae. Water transport across the Malpighian tubules of the larval mosquito is a critical physiological process because it is the first essential step in eliminating the excess water, a consequence of living in hypo‐osmotic habitats. Our study sheds light on the relative contribution of AQPs in this vital process. Support or Funding Information Natural Sciences and Engineering Research Council of Canada (NSERC) discovery grant awarded to Andrew Donini