An animal homolog of plant Mep/Amt transporters promotes ammonia excretion by the anal papillae of the disease vector mosquito,Aedes aegypti

Abstract

The transcripts of three putative ammonia (NH 3 /NH 4 + ) transporters, Rhesus-like glycoproteins AeRh50-1, AeRh50-2 and Amt/Mep-like AeAmt1 were detected in the anal papillae of larval Aedes aegypti. Quantitative PCR studies revealed 12-fold higher transcript levels of AeAmt1 in anal papillae relative to AeRh50-1, and levels of AeRh50-2 were even lower. Immunoblotting revealed AeAmt1 in anal papillae as a pre-protein with putative monomeric and trimeric forms. AeAmt1 was immunolocalized to the basal side of the anal papillae epithelium where it co-localized with Na +

Aedes aegypti Rhesus glycoproteins contribute to ammonia excretion by larval anal papillae

“…dsRNA synthesis, delivery to larvae and reversetranscription PCR (RT-PCR) dsRNA was prepared according to a previously established protocol (Chasiotis et al, 2016). Briefly, RNA was extracted from whole bodies of fourth instar A. aegypti larvae.…”

“…In the mosquito Aedes aegypti (Linnaeus in Hasselquist 1762), three putative ammonia transporters, AeRh50-1, AeRh50-2 and AeAmt1, were identified in silico (Weihrauch et al, 2012b) and the AeAmt1 was characterized in vivo (Chasiotis et al, 2016). The AeRh50-1 and AeRh50-2 genes share sequence similarity with other invertebrate and vertebrate Rh proteinss, and the Amt/Mep-like AeAmt1 is most similar to the bacterial AmtB (Chasiotis et al, 2016). The transcripts of AeRh50-1, AeRh50-2 and AeAmt1 were detected in the anal papillae of A. aegypti larvae, and a mechanism for ammonia excretion from the anal papillae involving the AeAmt1 was investigated (Chasiotis et al, 2016).…”

“…The AeRh50-1 and AeRh50-2 genes share sequence similarity with other invertebrate and vertebrate Rh proteinss, and the Amt/Mep-like AeAmt1 is most similar to the bacterial AmtB (Chasiotis et al, 2016). The transcripts of AeRh50-1, AeRh50-2 and AeAmt1 were detected in the anal papillae of A. aegypti larvae, and a mechanism for ammonia excretion from the anal papillae involving the AeAmt1 was investigated (Chasiotis et al, 2016). The anal papillae are finger-like structures composed of a single-layered syncytial epithelium which is externally covered by a thin cuticle (Credland, 1976).…”

“…The lumen of the anal papillae is continuous with the hemocoel of the body and the papillae are major sites of ammonia excretion in larval A. aegypti (Sohal and Copeland, 1966;Donini and O'Donnell, 2005). The AeAmt1 was localized to the basal membrane of the syncytial epithelium, where it was proposed to mediate NH 4 + entry into the cytosol driven by an electrical potential generated by the basal Na + /K + -ATPase (NKA) (Chasiotis et al, 2016).…”

“…Although not yet localized in the anal papillae, the transcript expression of AeRh50s in the anal papillae suggests that these transporters may also be important in both ammonia entry from the hemolymph into the cytosol, and excretion into the surrounding environment (Chasiotis et al, 2016). …”