In larval Aedes aegypti, transcripts of the Rhesus-like glycoproteins AeRh50-1 and AeRh50-2 have been detected in the anal papillae, sites of ammonia (NH3/NH4+) excretion; however, these putative ammonia transporters have not been previously localized or functionally characterized. In this study, we show that the AeRh50s co-immunolocalize with apical V-type H+-ATPase as well as with basal Na+/K+-ATPase in the epithelium of anal papillae. The double-stranded RNA-mediated knockdown of AeRh50-1 and AeRh50-2 resulted in a significant reduction in AeRh50 protein abundance in the anal papillae, and this was coupled to decreased ammonia excretion. The knockdown of AeRh50-1 resulted in decreased hemolymph [NH4+] and pH whereas knockdown of AeRh50-2 had no effect on these parameters. We conclude that the AeRh50s are important contributors to ammonia excretion at the anal papillae of larval A. aegypti, which may be the basis for their ability to inhabit areas with high ammonia levels.
The authors declare no competing or financial interests.
Conceptualization: A.D., A.C.D., H.C.; Methodology: A.D., H.C.; Formal analysis and investigation: A.C.D., A.D., H.C., L.M.; Writing - original draft preparation: A.C.D; Writing - review and editing: A.D., A.C.D.; Visualization: A.C.D., A.D., H.C., L.M.; Funding acquisition: A.D.; Resources: A.D.; Supervision: A.D.
This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant to A.D. and an Ontario Ministry of Research and Innovation Early Researcher Award to A.D.
- Received October 6, 2016.
- Accepted November 21, 2016.
- © 2017. Published by The Company of Biologists Ltd