Acid–Base Regulation in Insect Haemolymph

Matthews, Philip G. D.

doi:10.1007/978-3-319-39617-0_8

Cited by 11 publications

(9 citation statements)

References 89 publications

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“…Strategies of counteracting ion loss and water gain have been investigated in aquatic dipteran larvae, which have proven to be effective osmoregulators in varying environmental salinity (Akhter et al, 2017;Jonusaite et al, 2011;Nguyen and Donini, 2010;Patrick et al, 2001). Furthermore, aquatic invertebrates, and insects in particular, are among the most pH-tolerant animals on the planet (Matthews, 2017). Mosquito larvae have been shown to tolerate chronic exposure to highly alkaline or acidic water (pH 4-11) in nature and under laboratory conditions with minor effects on hemolymph pH, growth and development (Clark, 2004).…”

Section: Introductionmentioning

confidence: 99%

“…The regulation of hemolymph ion composition and pH, which are often linked, is essential for homeostasis and survival in freshwater systems with varying water chemistry. In addition to ventilation and buffering strategies, aquatic insects regulate their hemolymph pH and osmolarity through the active uptake and excretion of ions and acid-base equivalents internally between the hemolymph and gut lumen, or with the external environment (Matthews, 2017). For most air-breathing aquatic insects, such as mosquito larvae, ions and acid-base equivalents are absorbed or excreted directly between the hemolymph and the surroundings through ion-permeable epithelia.…”

Section: Introductionmentioning

confidence: 99%

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Evidence that Rh proteins in the anal papillae of the freshwater mosquitoAedes aegyptiare involved in the regulation of acid base balance in elevated salt and ammonia environments

Durant

Donini

2018

Journal of Experimental Biology

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Aedes aegypti commonly inhabit ammonia-rich sewage effluents in tropical regions of the world where the adults are responsible for the spread of disease. Studies have shown the importance of the anal papillae of A. aegypti in ion uptake and ammonia excretion. The anal papillae express ammonia transporters and Rhesus (Rh) proteins which are involved in ammonia excretion and studies have primarily focused on understanding these mechanisms in freshwater. In this study, effects of rearing larvae in salt (5 mmol l −1 NaCl) or ammonia (5 mmol l −1 NH 4 Cl) on physiological endpoints of ammonia and ion regulation were assessed. In anal papillae of NaCl-reared larvae, Rh protein expression increased, NHE3 transcript abundance decreased and NH 4 + excretion increased, and this coincided with decreased hemolymph [NH 4 + ] and pH. We propose that under these conditions, larvae excrete more NH 4 + through Rh proteins as a means of eliminating acid from the hemolymph. In anal papillae of NH 4 Clreared larvae, expression of an apical ammonia transporter and the Rh proteins decreased, the activities of NKA and VA decreased and increased, respectively, and this coincided with hemolymph acidification. The results present evidence for a role of Rh proteins in acid-base balance in response to elevated levels of salt, whereby ammonia is excreted as an acid equivalent.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Evidence that Rh proteins in the anal papillae of the freshwater mosquitoAedes aegyptiare involved in the regulation of acid base balance in elevated salt and ammonia environments

Durant

Donini

2018

Journal of Experimental Biology

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“…In insects, highly acidic gut regions have so far only rarely been described from the midgut ( Chapman, 2013 ; Holtof et al, 2019 ). The mechanisms responsible for the creation of a gut lumen compartment with a certain pH are often unknown in insects ( Harrison, 2001 ), but in principle, highly acidic gut regions in insects may, similar to vertebrates ( Hersey and Sachs, 1995 ), be generated through physiological mechanisms ( Matthews, 2017 ; Miguel-Aliaga et al, 2018 ; Onken and Moffett, 2017 ). Alternatively, acidic derivatives of gut-associated microbes ( Ratzke et al, 2018 , Ratzke and Gore, 2018 , Wolfe, 2005 ) or acidic gland secretions ( Blum, 1996 ; Morgan, 2008 ; Vander Meer, 2012 ) might contribute to the insect gut pH.…”

Section: Discussionmentioning

confidence: 99%

Formicine ants swallow their highly acidic poison for gut microbial selection and control

Tragust

Herrmann

Häfner

et al. 2020

eLife

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Animals continuously encounter microorganisms that are essential for health or cause disease. They are thus challenged to control harmful microbes while allowing the acquisition of beneficial microbes. This challenge is likely especially important for social insects with respect to microbes in food, as they often store food and exchange food among colony members. Here we show that formicine ants actively swallow their antimicrobial, highly acidic poison gland secretion. The ensuing acidic environment in the stomach, the crop, can limit the establishment of pathogenic and opportunistic microbes ingested with food and improve the survival of ants when faced with pathogen contaminated food. At the same time, crop acidity selectively allows acquisition and colonization by Acetobacteraceae, known bacterial gut associates of formicine ants. This suggests that swallowing of the poison in formicine ants acts as a microbial filter and that antimicrobials have a potentially widespread but so far underappreciated dual role in host-microbe interactions.

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“…Concurrent with the increase in oxygen consumption, pupae showed a marked suppression of CO 2 emission immediately after reperfusion that returned to baseline levels within ∼2 h. Anoxia is a strong stimulus for spiracle opening (Förster and Hetz, 2010), so spiracles of the pupae were likely open during anoxia, causing loss of CO 2 that must then be replaced during reperfusion (Matthews, 2016). Depressed CO 2 emission during reperfusion could also reflect increased CO 2 buffering in the hemolymph as lactate, acetate or other organic acids are removed from circulation when mitochondrial metabolism is reinitiated.…”

Section: Discussionmentioning

confidence: 99%

“…Depressed CO 2 emission during reperfusion could also reflect increased CO 2 buffering in the hemolymph as lactate, acetate or other organic acids are removed from circulation when mitochondrial metabolism is reinitiated. Manduca sexta pupae and adult rhinoceros beetles also experience transient decreases in CO 2 emission during reperfusion (Matthews, 2016;Woods and Lane, 2016), suggesting that this may be a general phenomenon (but see Lighton and Schilman, 2007). Drosophila melanogaster and M. sexta show an initial spike in CO 2 release immediately upon reperfusion (Lighton and Schilman, 2007;Woods and Lane, 2016).…”

Section: Discussionmentioning

confidence: 99%

Hormetic benefits of prior anoxia exposure in buffering anoxia stress in a soil-pupating insect

Visser

Williams

Hahn

et al. 2018

Journal of Experimental Biology

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Oxygen is essential for most animals, and exposure to a complete lack of oxygen, i.e. anoxia, can result in irreparable damage to cells that can extend up to the organismal level to negatively affect performance. Although it is known that brief anoxia exposure may confer cross-tolerance to other stressors, few data exist on the biochemical and organismal consequences of repeated intermittent bouts of anoxia exposure. In nature, the Caribbean fruit fly, (Diptera: Tephritidae), is frequently exposed to heavy tropical rainfall while pupating in the soil, equating to multiple exposures to hypoxia or anoxia during development. Here, we tested whether prior anoxia exposures during pupal development can induce a beneficial acclimation response, and we explored the consequences of prior exposure for both whole-organism performance and correlated biochemical metrics. Pharate adults (the last developmental stage in the pupal case) were most sensitive to anoxia exposure, showing decreased survival and fertility compared with controls. These negative impacts were ameliorated by exposure to anoxia in earlier pupal developmental stages, indicating a hormetic effect of prior anoxia exposure. Anoxia exposure early in pupal development reduced the oxygen debt repaid after anoxia exposure relative to pharate adults experiencing anoxia for the first time. Lipid levels were highest in all pupal stages when exposed to prior anoxia. Prior anoxia thus benefits organismal performance and relocates resources towards lipid storage throughout pupal-adult development.

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Acid–Base Regulation in Insect Haemolymph

Cited by 11 publications

References 89 publications

Evidence that Rh proteins in the anal papillae of the freshwater mosquitoAedes aegyptiare involved in the regulation of acid base balance in elevated salt and ammonia environments

Evidence that Rh proteins in the anal papillae of the freshwater mosquitoAedes aegyptiare involved in the regulation of acid base balance in elevated salt and ammonia environments

Formicine ants swallow their highly acidic poison for gut microbial selection and control

Hormetic benefits of prior anoxia exposure in buffering anoxia stress in a soil-pupating insect

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