Ammonia excretion in aquatic and terrestrial crabs

Weihrauch, Dirk; Morris, Steve; Towle, David W.

doi:10.1242/jeb.01308

Cited by 215 publications

(185 citation statements)

References 102 publications

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“…Furthermore, the levels of ammonia in the hemolymph of insects in comparison to other animals demonstrate their increased tolerance to this toxic molecule (see Weihrauch et al, 2012b). For example, Drosophila melanogaster larvae feed and develop in media containing up to 30 mmol l −1 ammonia (Borash et al, 1998), and the ammonia hemolymph levels of black flies (5 mmol l −1 ; Gordon and Bailey, 1974), Manduca sexta larvae (0.8 mmol l −1 ; Weihrauch, 2006) and larval A. aegypti (up to ∼1.5 mmol l −1 ; Chasiotis et al, 2016) are much higher than those of aquatic crabs (Weihrauch et al, 1999) and mammals (Cooper and Plum, 1987), where levels are no greater than 400 μmol l −1 (see Weihrauch et al, 2004). Environmental ammonia levels as low as 19 μmol l −1 NH 3 are lethal to crustaceans (Ostrensky et al, 1992), but remarkably, A. aegypti larvae exposed to 1 mmol l −1 NH 4 Cl for 3 days not only survive, but also quickly adjust to the HEA conditions by increasing NH 4 + and H + excretion from the anal papillae (Weihrauch et al, 2012b).…”

Section: Multiple Mechanisms Of Ammonia Excretion By Larval Mosquitoesmentioning

confidence: 99%

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

Durant

Chasiotis

Misyura

et al. 2016

Journal of Experimental Biology

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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 (NH 3 /NH 4 + ) 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 doublestranded 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 [NH 4 + ] 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.

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Section: Multiple Mechanisms Of Ammonia Excretion By Larval Mosquitoesmentioning

confidence: 99%

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

Durant

Chasiotis

Misyura

et al. 2016

Journal of Experimental Biology

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“…The high lipid solubility of ammonia makes it more diffusible through phospholipid bilayers. The mechanism supporting ammonia excretion in crustaceans is the simple diffusion of the non-ionic NH 3 along a concentration gradient and the partial excretion of the ionised form NH 4 + , whose release through diffusion is facilitated because of its hydrophobicity (Weihrauch et al, 1999(Weihrauch et al, , 2004. Several aquatic crab species possess an excretion system based on the ionised form of ammonia, NH 4 + , a water soluble compound which effluxes through the gill epithelium.…”

Section: Histological Effectsmentioning

confidence: 99%

“…Ammonia toxicity is mediated by the excessive activation of N-methyl-D-aspartate (NMDA)-type glutamate receptors in the brain. As a consequence, cerebral ATP is depleted, while intracellular Ca 2+ increases, with subsequent increases in intracellular K + and, finally, cell death (Weihrauch et al, 1999(Weihrauch et al, , 2004. The intensity of the observed effects is related to pesticide concentration and animal resistance.…”

Section: Histological Effectsmentioning

confidence: 99%

Freshwater Decapods and Pesticides: An Unavoidable Relation in the Modern World

Negro¹,

Senkman²,

Montagna³

et al. 2011

Pesticides in the Modern World - Risks and Benefits

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“…Studies in mammalian and plant systems reveal that at least some of those Rh genes encode proteins that mediate NH 3 /NH 4 + movement (Khademi et al, 2004;Zheng et al, 2004;Mayer et al, 2006), but the form of ammonia (NH 3 gas or NH 4 + ion) being transported, and whether the transport is active or passive, are still under much debate (Bakouh et al, 2004;Khademi et al, 2004;Nakhoul et al, 2005). A fulllength cDNA of Rh-like protein (Rh-CM) has been identified recently from the gills of the aquatic crab Carcinus maenas, which has a similar predicted transmembrane structure as the mammalian Rh proteins (Weihrauch et al, 2004). However, the precise role of Rh-CM in crab ammonia excretion awaits elucidation.…”

Section: Introductionmentioning

confidence: 99%

Rhesus glycoprotein gene expression in the mangrove killifishKryptolebias marmoratusexposed to elevated environmental ammonia levels and air

Hung

Tsui

Wilson³

et al. 2007

Journal of Experimental Biology

116

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SUMMARY The mechanism(s) of ammonia excretion in the presence of elevated external ammonia are not well understood in fish. Recent studies in other organisms have revealed a new class of ammonia transporters, Rhesus glycoprotein genes(Rh genes), which may also play a role in ammonia excretion in fish. The first objective of this study was to clone and characterize Rhgenes in a fish species with a relatively high tolerance to environmental ammonia, the mangrove killifish Kryptolebias marmoratus (formerly Rivulus marmoratus). We obtained full-length cDNAs of three Rh genes in K. marmoratus: RhBG (1736 bp), RhCG1 (1920 bp) and RhCG2 (2021 bp), which are highly homologous with other known Rh gene sequences. Hydropathy analysis revealed that all three Rh genes encode membrane proteins with 10–12 predicted transmembrane domains. RhBG, RhCG1 and RhCG2 are highly expressed in gill tissue, with RhBG also present in skin of K. marmoratus. Exposure to elevated environmental ammonia (2 mmol l–1 NH4HCO3) for 5 days resulted in a modest (+37%) increase in whole-body ammonia levels, whereas gill RhCG2 and skin RhCG1 mRNA levels were upregulated by 5.8- and 7.7-fold, respectively. RhBG mRNA levels were also increased in various tissues, with 3- to 7-fold increases in the liver and skeletal muscle. In a separate group of killifish exposed to air for 24 h, RhCG1 and RhCG2 mRNA levels were elevated by 4- to 6-fold in the skin. Thus, the multifold induction of Rh mRNA levels in excretory tissues (gills and skin) and internal tissues in response to conditions that perturb normal ammonia excretion suggests that RhBG, RhCG1 and RhCG2 may be involved in facilitating ammonia transport in this species. Furthermore, the findings support earlier studies demonstrating that the skin is an important site of ammonia excretion in K. marmoratus.

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Ammonia excretion in aquatic and terrestrial crabs

Cited by 215 publications

References 102 publications

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

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

Freshwater Decapods and Pesticides: An Unavoidable Relation in the Modern World

Rhesus glycoprotein gene expression in the mangrove killifishKryptolebias marmoratusexposed to elevated environmental ammonia levels and air

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