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Clark JT, Ganguly A, Ejercito J, Luy M, Dahanukar A, Ray A. Chemosensory detection of aversive concentrations of ammonia and basic volatile amines in insects. iScience 2022; 26:105777. [PMID: 36594011 PMCID: PMC9804102 DOI: 10.1016/j.isci.2022.105777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 09/09/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Basic volatiles like ammonia are found in insect environments, and at high concentrations cause an atypical action potential burst, followed by inhibition in multiple classes of olfactory receptor neurons (ORNs) in Drosophila melanogaster. During the period of inhibition, ORNs are unable to fire action potentials to their ligands but continue to display receptor potentials. An increase in calcium is also observed in antennal cells of Drosophila and Aedes aegypti. In the gustatory system, ammonia inhibits sugar and salt responses in a dose-dependent manner. Other amines show similar effects in both gustatory and olfactory neurons, correlated with basicity. The concentrations that inhibit neurons reduce proboscis extension to sucrose in Drosophila. In Aedes, a brief exposure to volatile ammonia abolishes attraction to human skin odor for several minutes. These findings reveal an effect that prevents detection of attractive ligands in the olfactory and gustatory systems and has potential in insect control.
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Affiliation(s)
- Jonathan Trevorrow Clark
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, CA 92521, USA
| | - Anindya Ganguly
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, CA 92521, USA
| | - Jadrian Ejercito
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Matthew Luy
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Anupama Dahanukar
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, CA 92521, USA,Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Anandasankar Ray
- Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, CA 92521, USA,Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, CA 92521, USA,Corresponding author
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2
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Goiran C, Shine T, Shine R. The banded colour patterns of sea snakes discourage attack by predatory fishes, enabling Batesian mimicry by harmless species. Proc Biol Sci 2022; 289:20221759. [PMID: 36382516 PMCID: PMC9667369 DOI: 10.1098/rspb.2022.1759] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/30/2022] [Indexed: 02/26/2024] Open
Abstract
The evolution of bright 'warning' colours in nontoxic animals often is attributed to mimicry of toxic species, but empirical tests of that hypothesis must overcome the logistical challenge of quantifying differential rates of predation in nature. Populations of a harmless sea snake species (Emydocephalus annulatus) in New Caledonia exhibit colour polymorphism, with around 20% of individuals banded rather than melanic. Stability in that proportion over 20 years has been attributed to Batesian mimicry of deadly snake species by banded morphs of the harmless taxon. This hypothesis requires that banded colours reduce a snake's vulnerability to predation. We tested that idea by pulling flexible snake-shaped models through the water and recording responses by predatory fish. Black and banded lures attracted similar numbers of following fish, but attacks were directed almost exclusively to black lures. Our methods overcome several ambiguities associated with experimental studies on mimicry in terrestrial snakes and support the hypothesis that banded colour patterns reduce a non-venomous marine snake's vulnerability to predation.
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Affiliation(s)
- Claire Goiran
- LabEx Corail & ISEA, Université de la Nouvelle-Calédonie, BP R4, 98851 Nouméa cedex, New Caledonia
| | - Terri Shine
- School of Natural Sciences, Macquarie University, New South Wales 2109, Australia
| | - Richard Shine
- School of Natural Sciences, Macquarie University, New South Wales 2109, Australia
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3
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Ramiro IBL, Bjørn-Yoshimoto WE, Imperial JS, Gajewiak J, Salcedo PF, Watkins M, Taylor D, Resager W, Ueberheide B, Bräuner-Osborne H, Whitby FG, Hill CP, Martin LF, Patwardhan A, Concepcion GP, Olivera BM, Safavi-Hemami H. Somatostatin venom analogs evolved by fish-hunting cone snails: From prey capture behavior to identifying drug leads. SCIENCE ADVANCES 2022; 8:eabk1410. [PMID: 35319982 PMCID: PMC8942377 DOI: 10.1126/sciadv.abk1410] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
Somatostatin (SS) is a peptide hormone with diverse physiological roles. By investigating a deep-water clade of fish-hunting cone snails, we show that predator-prey evolution has generated a diverse set of SS analogs, each optimized to elicit specific systemic physiological effects in prey. The increased metabolic stability, distinct SS receptor activation profiles, and chemical diversity of the venom analogs make them suitable leads for therapeutic application, including pain, cancer, and endocrine disorders. Our findings not only establish the existence of SS-like peptides in animal venoms but also serve as a model for the synergy gained from combining molecular phylogenetics and behavioral observations to optimize the discovery of natural products with biomedical potential.
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Affiliation(s)
- Iris Bea L. Ramiro
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen-N 2200, Denmark
- The Marine Science Institute, University of the Philippines, Quezon City 1101, Philippines
| | | | - Julita S. Imperial
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Joanna Gajewiak
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Paula Flórez Salcedo
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84112, USA
| | - Maren Watkins
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Dylan Taylor
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - William Resager
- New York University Langone Medical Center, New York, NY 10016, USA
| | | | - Hans Bräuner-Osborne
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen-Ø 2100, Denmark
| | - Frank G. Whitby
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Christopher P. Hill
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Laurent F. Martin
- Department of Anesthesiology and Pharmacology, University of Arizona, Tucson, AZ 85724, USA
| | - Amol Patwardhan
- Department of Anesthesiology and Pharmacology, University of Arizona, Tucson, AZ 85724, USA
| | - Gisela P. Concepcion
- The Marine Science Institute, University of the Philippines, Quezon City 1101, Philippines
| | - Baldomero M. Olivera
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Helena Safavi-Hemami
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen-N 2200, Denmark
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, USA
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4
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Resetarits WJ, Breech TM, Bohenek JR, Pintar MR. Cue reduction or general cue masking do not underlie generalized chemical camouflage in pirate perch. Ecology 2021; 103:e3625. [PMID: 34970743 DOI: 10.1002/ecy.3625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 06/16/2021] [Accepted: 07/20/2021] [Indexed: 11/06/2022]
Abstract
Avoiding detection is perhaps the ultimate weapon for both predators and prey. Chemosensory detection of predators via waterborne or airborne cues (predator-released kairomones) is a key prey adaptation in aquatic ecosystems. Pirate perch, Aphredoderus sayanus, a largely insectivorous mesopredatory fish, are considered to be chemically camouflaged because they are unavoided by all colonizing organisms tested, including treefrogs and aquatic insects, despite stronger predatory effects on target taxa than several avoided fish. To address the mechanism behind camouflage we used aquatic insect colonization as a bioassay to test 1) whether increasing pirate perch density/biomass leads to increased avoidance, and 2) whether pirate perch mask heterospecific fish kairomones. Insect abundances, species richness, and community structure showed no response to pirate perch density. Lastly, pirate perch did not mask the kairomones of heterospecific predatory fish. Results support the idea that fish kairomones are species-specific, and chemical camouflage is driven by a unique chemical signature that is either undetectable or has no negative associations for colonizers.
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Affiliation(s)
- William J Resetarits
- Department of Biology and Centers for Water and Wetlands Resources, and Biodiversity and Conservation Research, The University of Mississippi, University, MS
| | - Tyler M Breech
- Department of Biology and Centers for Water and Wetlands Resources, and Biodiversity and Conservation Research, The University of Mississippi, University, MS
| | - Jason R Bohenek
- Department of Biology and Centers for Water and Wetlands Resources, and Biodiversity and Conservation Research, The University of Mississippi, University, MS
| | - Matthew R Pintar
- Department of Biology and Centers for Water and Wetlands Resources, and Biodiversity and Conservation Research, The University of Mississippi, University, MS
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5
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Cartolano MC, Tullis-Joyce P, Kubicki K, McDonald MD. Do Gulf Toadfish Use Pulsatile Urea Excretion to Chemically Communicate Reproductive Status? Physiol Biochem Zool 2019; 92:125-139. [PMID: 30657409 DOI: 10.1086/701497] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Gulf toadfish (Opsanus beta) are exceptionally capable of switching from excreting ammonia as their primary nitrogenous waste to excreting predominantly urea in distinct pulses across the gill. Previous studies suggest that these urea pulses may be used for intraspecific chemical communication. To determine whether pulsatile urea excretion communicates reproductive status, toadfish were sexed using ultrasound and delivered conspecific-conditioned seawater (CC-SW) that previously housed a conspecific of the opposite sex, a conspecific chemical alarm cue (avoidance control), or a prey cue (attraction control). Swim behavior, attraction to or avoidance of the cues, and changes in the pattern of pulsatile urea excretion were monitored during and after delivery. Gulf toadfish did not spend more time in zones that were delivered CC-SW or prey cue. However, male toadfish spent significantly more time swimming after the delivery of female cues than control seawater (SW). In contrast, toadfish did not appear to have an immediate avoidance response to the conspecific alarm cue. Additionally, significantly more toadfish pulsed within 7 h of CC-SW and prey cue delivery compared to control SW, and pulse frequency was 1.6 times greater in response to CC-SW than control SW. These results, in combination with increased urea production and excretion the during breeding season, suggest that toadfish may use pulsatile urea excretion to communicate with conspecifics when exposed to chemosensory cues from the opposite sex.
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6
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Bairos-Novak KR, Mitchell MD, Crane AL, Chivers DP, Ferrari MCO. Trust thy neighbour in times of trouble: background risk alters how tadpoles release and respond to disturbance cues. Proc Biol Sci 2018; 284:rspb.2017.1465. [PMID: 28954912 DOI: 10.1098/rspb.2017.1465] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/30/2017] [Indexed: 02/03/2023] Open
Abstract
In aquatic environments, uninjured prey escaping a predator release chemical disturbance cues into the water. However, it is unknown whether these cues are a simple physiological by-product of increased activity or whether they represent a social signal that is under some control by the sender. Here, we exposed wood frog tadpoles (Lithobates sylvaticus) to either a high or low background risk environment and tested their responses to disturbance cues (or control cues) produced by tadpoles from high-risk or low-risk backgrounds. We found an interaction between risk levels associated with the cue donor and cue recipient. While disturbance cues from low-risk donors did not elicit an antipredator response in low-risk receivers, they did in high-risk receivers. In addition, disturbance cues from high-risk donors elicited a marked antipredator response in both low- and high-risk receivers. The response of high-risk receivers to disturbance cues from high-risk donors was commensurate with other treatments, indicating an all-or-nothing response. Our study provides evidence of differential production and perception of social cues and provides insights into their function and evolution in aquatic vertebrates. Given the widespread nature of disturbance cues in aquatic prey, there may exist a social signalling system that remains virtually unexplored by ecologists.
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Affiliation(s)
- Kevin R Bairos-Novak
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, Canada S7N 5E2
| | - Matthew D Mitchell
- Department of Veterinary Biomedical Sciences, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, Canada S7N 5B4
| | - Adam L Crane
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, Canada S7N 5E2
| | - Douglas P Chivers
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, Canada S7N 5E2
| | - Maud C O Ferrari
- Department of Veterinary Biomedical Sciences, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, Canada S7N 5B4
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7
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Cardinal EA, Radford CA, Mensinger AF. The potential for the anterior lateral line to function for sound localization in toadfish (Opsanus tau). J Exp Biol 2018; 221:jeb.180679. [DOI: 10.1242/jeb.180679] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 09/21/2018] [Indexed: 01/04/2023]
Abstract
Male oyster toadfish (Opsanus tau) acoustically attract females to nesting sites using a boatwhistle call. The rapid speed of sound underwater combined with the close proximity of the otolithic organs makes inner ear interaural time differences an unlikely mechanism to localize sound. To determine the role that the mechanosensory lateral line may play in sound localization, microwire electrodes were bilaterally implanted into the anterior lateral line nerve to record neural responses to vibrational stimuli. Highest spike rates and strongest phase-locking occurred at distances close to the fish and decreased as the stimulus was moved further from the fish. Bilateral anterior lateral line neuromasts displayed differential directional sensitivity to incoming vibrational stimuli, which suggests the potential for the lateral line to be used for sound localization in the near field. The present study also demonstrates that the spatially separated neuromasts of the toadfish may provide sufficient time delays between sensory organs for determining sound localization cues. Multimodal sensory input processing through both the inner ear (far field) and lateral line (near field) may allow for effective sound localization in fish.
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Affiliation(s)
- Emily A. Cardinal
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
- Biology Department, University of Minnesota Duluth, Duluth, MN 55812, USA
| | - Craig A. Radford
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
- Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, Warkworth 0941, New Zealand
| | - Allen F. Mensinger
- Marine Biological Laboratory, Woods Hole, MA 02543, USA
- Biology Department, University of Minnesota Duluth, Duluth, MN 55812, USA
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8
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Brooker RM, Munday PL, Chivers DP, Jones GP. You are what you eat: diet-induced chemical crypsis in a coral-feeding reef fish. Proc Biol Sci 2015; 282:20141887. [PMID: 25621328 DOI: 10.1098/rspb.2014.1887] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The vast majority of research into the mechanisms of camouflage has focused on forms that confound visual perception. However, many organisms primarily interact with their surroundings using chemosensory systems and may have evolved mechanisms to 'blend in' with chemical components of their habitat. One potential mechanism is 'chemical crypsis' via the sequestration of dietary elements, causing a consumer's odour to chemically match that of its prey. Here, we test the potential for chemical crypsis in the coral-feeding filefish, Oxymonacanthus longirostris, by examining olfactory discrimination in obligate coral-dwelling crabs and a predatory cod. The crabs, which inhabit the corals consumed by O. longirostris, were used as a bioassay to determine the effect of coral diet on fish odour. Crabs preferred the odour of filefish fed their preferred coral over the odour of filefish fed a non-preferred coral, suggesting coral-specific dietary elements that influence odour are sequestered. Crabs also exhibited a similar preference for the odour of filefish fed their preferred coral and odour directly from that coral, suggesting a close chemical match. In behavioural trials, predatory cod were less attracted to filefish odour when presented alongside the coral it had been fed on, suggesting diet can reduce detectability. This is, we believe, the first evidence of diet-induced chemical crypsis in a vertebrate.
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LeMoine CMR, Walsh PJ. Evolution of urea transporters in vertebrates: adaptation to urea's multiple roles and metabolic sources. J Exp Biol 2015; 218:1936-45. [PMID: 26085670 DOI: 10.1242/jeb.114223] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In the two decades since the first cloning of the mammalian kidney urea transporter (UT-A), UT genes have been identified in a plethora of organisms, ranging from single-celled bacteria to metazoans. In this review, focusing mainly on vertebrates, we first reiterate the multiple catabolic and anabolic pathways that produce urea, then we reconstruct the phylogenetic history of UTs, and finally we examine the tissue distribution of UTs in selected vertebrate species. Our analysis reveals that from an ancestral UT, three homologues evolved in piscine lineages (UT-A, UT-C and UT-D), followed by a subsequent reduction to a single UT-A in lobe-finned fish and amphibians. A later internal tandem duplication of UT-A occurred in the amniote lineage (UT-A1), followed by a second tandem duplication in mammals to give rise to UT-B. While the expected UT expression is evident in excretory and osmoregulatory tissues in ureotelic taxa, UTs are also expressed ubiquitously in non-ureotelic taxa, and in tissues without a complete ornithine-urea cycle (OUC). We posit that non-OUC production of urea from arginine by arginase, an important pathway to generate ornithine for synthesis of molecules such as polyamines for highly proliferative tissues (e.g. testis, embryos), and neurotransmitters such as glutamate for neural tissues, is an important evolutionary driving force for the expression of UTs in these taxa and tissues.
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Affiliation(s)
- Christophe M R LeMoine
- Department of Biology, Centre for Advanced Research in Environmental Genomics, University of Ottawa, 30 Marie Curie, Ottawa, ON, Canada, K1N 6N5
| | - Patrick J Walsh
- Department of Biology, Centre for Advanced Research in Environmental Genomics, University of Ottawa, 30 Marie Curie, Ottawa, ON, Canada, K1N 6N5
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Ferrando S, Gallus L, Gambardella C, Marchesotti E, Ravera S, Franceschini V, Masini MA. Effects of urea on the molecules involved in the olfactory signal transduction: a preliminary study on Danio rerio. FISH PHYSIOLOGY AND BIOCHEMISTRY 2014; 40:1793-1800. [PMID: 25092237 DOI: 10.1007/s10695-014-9968-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 07/24/2014] [Indexed: 06/03/2023]
Abstract
Among vertebrates, the physiologically uremic Chondrichthyes are the only class which are not presenting the ciliated olfactory receptor neurons in the olfactory neuroepithelium. The only sequenced genome for this class revealed only three olfactory receptor genes and the immunohistochemical detection of G protein alpha subunit typically coupled to the olfactory receptors (Gα(olf)) failed in different species. Chronic renal disease can represent a cause of olfactory impairment in human. In this context, our present study focused on investigating potential effects of high urea concentration on the olfactory epithelium of vertebrates. Larvae of the teleost fish Danio rerio were exposed to urea in order to assess the effects on the olfactory signal transduction; in particular on both the olfactory receptors and the Gα(olf). The endocytosis of neutral red dye in the olfactory mucosa was detected in control and urea-exposed larvae. The amount of neutral red dye uptake was used as a marker of binding and internalization of the Gα(olf). The neutral red dye endocytosis was not affected by urea exposure, hence suggesting that the presence of the Gα(olf) and their binding to the odorants are not affected by urea treatment, either. The presence and distribution of Gα(olf) were investigated in the olfactory epithelium of control and urea-exposed larvae, using a commercial antibody. The immunoreactivity was increased after urea treatment, suggesting an effect of urea on the expression or degradation of this G protein alpha subunit.
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Affiliation(s)
- Sara Ferrando
- DISTAV, University of Genoa, Viale Benedetto XV 5, 16132, Genoa, Italy,
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11
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Larsen EH, Deaton LE, Onken H, O'Donnell M, Grosell M, Dantzler WH, Weihrauch D. Osmoregulation and Excretion. Compr Physiol 2014; 4:405-573. [DOI: 10.1002/cphy.c130004] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Bucking C, Edwards SL, Tickle P, Smith CP, McDonald MD, Walsh PJ. Immunohistochemical localization of urea and ammonia transporters in two confamilial fish species, the ureotelic gulf toadfish (Opsanus beta) and the ammoniotelic plainfin midshipman (Porichthys notatus). Cell Tissue Res 2013; 352:623-37. [PMID: 23512140 DOI: 10.1007/s00441-013-1591-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 02/14/2013] [Indexed: 12/29/2022]
Abstract
This study aims to illustrate potential transport mechanisms behind the divergent approaches to nitrogen excretion seen in the ureotelic toadfish (Opsanus beta) and the ammoniotelic plainfin midshipman (Porichthys notatus). Specifically, we wish to confirm the expression of a urea transporter (UT), which is found in the gill of the toadfish and which is responsible for the unique "pulsing" nature of urea excretion and to localize the transporter within specific gill cells and at specific cellular locations. Additionally, the localization of ammonia transporters (Rhesus glycoproteins; Rhs) within the gill of both the toadfish and midshipman was explored. Toadfish UT (tUT) was found within Na(+)-K(+)-ATPase (NKA)-enriched cells, i.e., ionocytes (probably mitochondria-rich cells), especially along the basolateral membrane and potentially on the apical membrane. In contrast, midshipman UT (pnUT) immunoreactivity did not colocalize with NKA immunoreactivity and was not found along the filaments but instead within the lamellae. The cellular location of Rh proteins was also dissimilar between the two fish species. In toadfish gills, the Rh isoform Rhcg1 was expressed in both NKA-reactive cells and non-reactive cells, whereas Rhbg and Rhcg2 were only expressed in the latter. In contrast, Rhbg, Rhcg1 and Rhcg2 were expressed in both NKA-reactive and non-reactive cells of midshipman gills. In an additional transport epithelium, namely the intestine, the expression of both UTs and Rhs was similar between the two species, with only subtle differences being observed.
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Affiliation(s)
- Carol Bucking
- Department of Biology, University of Ottawa, Ottawa, ON, Canada.
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13
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Frere AW, McDonald MD. The effect of stress on gill basolateral membrane binding kinetics of 5-ht2 receptor ligands: potential implications for urea excretion mechanisms. ACTA ACUST UNITED AC 2013; 319:237-48. [PMID: 23495168 DOI: 10.1002/jez.1788] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 11/13/2012] [Accepted: 02/06/2013] [Indexed: 11/07/2022]
Abstract
The goal of this study was to determine the relationship between cortisol and the toadfish serotonin 2A (5-HT2A ) receptor, which is believed to be responsible for the activation of the toadfish urea transporter, tUT. We hypothesize that elevations in cortisol would play a role in the regulation of the 5-HT2A receptor at the level of mRNA expression, ligand binding, and/or function. To test this idea, cortisol levels were manipulated by either crowding or through treatment with the cortisol synthesis blocker, metyrapone. Crowded fish had significantly higher circulating cortisol levels compared to uncrowded fish and cortisol levels in metyrapone-treated fish were significantly lower than saline-treated controls. No significant difference was measured in gill 5-HT2A mRNA expression levels between uncrowded and crowded, control- or metyrapone-treated fish. Furthermore, no significant difference was measured in [(3) H]-5-HT binding kinetics or in the competitive binding of the 5-HT2 agonist, α-methyl 5-HT, to isolated gill basolateral membranes of uncrowded or crowded toadfish. However, the binding maximum (Bmax ) of the 5-HT2A receptor antagonist, [(3) H]-ketanserin, was significantly different between all four groups of fish (metyrapone > control > crowded > uncrowded). Furthermore, metyrapone-treated fish excreted approximately twofold more urea compared to controls when injected with α-methyl 5-HT, a 5-HT2 receptor agonist shown to stimulate urea excretion. Our results suggest that cortisol may have differential effects on 5-HT receptor binding, which could have potential implications on the control of pulsatile urea excretion in toadfish.
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Affiliation(s)
- Alexander W Frere
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA
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14
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Resetarits WJ, Binckley CA. Is the pirate really a ghost? Evidence for generalized chemical camouflage in an aquatic predator, pirate perch Aphredoderus sayanus. Am Nat 2013; 181:690-9. [PMID: 23594551 DOI: 10.1086/670016] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Camouflage occupies a central role in arsenals of both predators and prey and invokes visions of organisms possessing specific characteristics or altering their shape, color, or behavior to blend into the visual background or confound identification. However, many organisms use modalities other than vision. Chemical communication is particularly important in aquatic systems, and chemicals cues are used by a broad array of colonizing organisms to recognize and avoid risky habitats. Here we describe a habitat selection experiment with aquatic beetles and summarize results of 11 experiments involving colonizing beetles and ovipositing tree frogs that provide evidence that pirate perch Aphredoderus sayanus are chemically camouflaged with respect to a diverse array of prey organisms. We believe this to be the first example of a predator possessing a generalized chemical camouflage effective against a broad array of prey organisms, and we suggest that it may constitute a novel weapon in the predator-prey arms race.
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Affiliation(s)
- William J Resetarits
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas 79409, USA.
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15
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5-Hydroxytryptamine initiates pulsatile urea excretion from perfused gills of the gulf toadfish (Opsanus beta). Comp Biochem Physiol A Mol Integr Physiol 2012; 163:30-7. [DOI: 10.1016/j.cbpa.2012.04.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 04/25/2012] [Accepted: 04/25/2012] [Indexed: 11/22/2022]
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16
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Mager EM, Medeiros LR, Lange AP, McDonald MD. The toadfish serotonin 2A (5-HT(2A)) receptor: molecular characterization and its potential role in urea excretion. Comp Biochem Physiol A Mol Integr Physiol 2012; 163:319-26. [PMID: 22884998 DOI: 10.1016/j.cbpa.2012.07.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 07/24/2012] [Accepted: 07/25/2012] [Indexed: 12/20/2022]
Abstract
Based on early pharmacological work, the serotonin 2A (5-HT(2A)) receptor subtype is believed to be involved in the regulation of toadfish pulsatile urea excretion. The goal of the following study was to characterize the toadfish 5-HT(2A) receptor at a molecular level, to determine the tissues in which this receptor is predominantly expressed and to further investigate the pharmacological specificity of toadfish pulsatile urea excretion by examining the effect of ketanserin, a 5-HT(2A) receptor antagonist, on resting rates of pulsatile urea excretion. The full-length toadfish 5-HT(2A) receptor encodes a 496 amino acid sequence and shares 57-80% sequence identity to 5-HT(2A) receptors of other organisms, with 100% conservation among important ligand-binding residues. Toadfish 5-HT(2A) receptor mRNA expression was highest in the swim bladder and gonad, followed by the whole brain. All other tissues tested (esophagus, stomach, anterior intestine, posterior intestine, rectum, liver, kidney, heart, muscle and gill) had mRNA expression levels that were significantly less than whole brain. Toadfish 5-HT(2A) receptor mRNA expression within the brain was highest in the hindbrain, telencephalon and midbrain/diencephalon regions. Treatment with the 5-HT(2A) receptor antagonist, ketanserin, resulted in a significant decrease in the pulsatile component of spontaneous urea excretion due to a reduction in urea pulse size with no significant change in pulse frequency. These results lend further support for the 5-HT(2A) receptor in the regulation of pulsatile urea excretion in toadfish.
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Affiliation(s)
- Edward M Mager
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA
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McDonald MD, Gilmour KM, Walsh PJ. New insights into the mechanisms controlling urea excretion in fish gills. Respir Physiol Neurobiol 2012; 184:241-8. [PMID: 22684040 DOI: 10.1016/j.resp.2012.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 05/31/2012] [Accepted: 06/01/2012] [Indexed: 12/28/2022]
Abstract
Not long ago, urea was believed to freely diffuse across plasma membranes. The discovery of specialized proteins to facilitate the movement of urea across the fish gill, similar to those found in mammalian kidney, was exciting, and at the same time, perplexing; especially considering the fact that, aside from elasmobranchs, most fish do not produce urea as their primary nitrogenous waste. Increasingly, it has become apparent that many fish do indeed produce at least a small amount of urea through various processes and continued work on branchial urea transporters in teleost and elasmobranch fishes has led to recent advances in the regulation of these mechanisms. The following review outlines the substantial progress that has been made towards understanding environmental and developmental impacts on fish gill urea transport. This review also outlines the work that has been done regarding endocrine and neural control of urea excretion, most of which has been collected from only a handful of teleost fish. It is evident that more research is needed to establish the endocrine and neural control of urea excretion in fish, including fish representative of more ancient lineages (hagfish and lamprey), and elasmobranch fish.
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Affiliation(s)
- M Danielle McDonald
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA.
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Rodela TM, McDonald MD, Walsh PJ, Gilmour KM. Interactions between cortisol and Rhesus glycoprotein expression in ureogenic toadfish, Opsanus beta. J Exp Biol 2012; 215:314-23. [DOI: 10.1242/jeb.061895] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
SUMMARY
In their native environment, gulf toadfish excrete equal quantities of ammonia and urea. However, upon exposure to stressful conditions in the laboratory (i.e. crowding, confinement or air exposure), toadfish decrease branchial ammonia excretion and become ureotelic. The objective of this study was to determine the influences of cortisol and ammonia on ammonia excretion relative to expression of Rhesus (Rh) glycoproteins and the ammonia-fixing enzyme, glutamine synthetase (GS). In vivo infusions and/or injections were used to manipulate corticosteroid activity and plasma ammonia concentrations in ureotelic toadfish. Metyrapone treatment to lower circulating cortisol levels resulted in a 3.5-fold elevation of ammonia excretion rates, enhanced mRNA expression of two of the toadfish Rh isoforms (Rhcg1 and Rhcg2), and decreased branchial and hepatic GS activity. Correspondingly, cortisol infusion decreased ammonia excretion 2.5-fold, a change that was accompanied by reduced branchial expression of all toadfish Rh isoforms (Rhag, Rhbg, Rhcg1 and Rhcg2) and a twofold increase in hepatic GS activity. In contrast, maintenance of high circulating ammonia levels by ammonia infusion enhanced ammonia excretion and Rh expression (Rhag, Rhbg and Rhcg2). Toadfish treated with cortisol showed an attenuated response to ammonia infusion with no change in Rh mRNA expression or GS activity. In summary, the evidence suggests that ammonia excretion in toadfish is modulated by cortisol-induced changes in both Rh glycoprotein expression and GS activity.
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Affiliation(s)
- Tamara M. Rodela
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5
| | - M. Danielle McDonald
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149-1098, USA
| | - Patrick J. Walsh
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5
| | - Kathleen M. Gilmour
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5
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Barimo JF, Walsh PJ, McDonald MD. Diel Patterns of Nitrogen Excretion, Plasma Constituents, and Behavior in the Gulf Toadfish (Opsanus beta) in Laboratory versus Outdoor Mesocosm Settings. Physiol Biochem Zool 2010; 83:958-72. [DOI: 10.1086/656427] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Ip YK, Chew SF. Ammonia production, excretion, toxicity, and defense in fish: a review. Front Physiol 2010; 1:134. [PMID: 21423375 PMCID: PMC3059970 DOI: 10.3389/fphys.2010.00134] [Citation(s) in RCA: 164] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Accepted: 09/06/2010] [Indexed: 12/20/2022] Open
Abstract
Many fishes are ammonotelic but some species can detoxify ammonia to glutamine or urea. Certain fish species can accumulate high levels of ammonia in the brain or defense against ammonia toxicity by enhancing the effectiveness of ammonia excretion through active NH4+transport, manipulation of ambient pH, or reduction in ammonia permeability through the branchial and cutaneous epithelia. Recent reports on ammonia toxicity in mammalian brain reveal the importance of permeation of ammonia through the blood-brain barrier and passages of ammonia and water through transporters in the plasmalemma of brain cells. Additionally, brain ammonia toxicity could be related to the passage of glutamine through the mitochondrial membranes into the mitochondrial matrix. On the other hand, recent reports on ammonia excretion in fish confirm the involvement of Rhesus glycoproteins in the branchial and cutaneous epithelia. Therefore, this review focuses on both the earlier literature and the up-to-date information on the problems and mechanisms concerning the permeation of ammonia, as NH(3), NH4+ or proton-neutral nitrogenous compounds, across mitochondrial membranes, the blood-brain barrier, the plasmalemma of neurons, and the branchial and cutaneous epithelia of fish. It also addresses how certain fishes with high ammonia tolerance defend against ammonia toxicity through the regulation of the permeation of ammonia and related nitrogenous compounds through various types of membranes. It is hoped that this review would revive the interests in investigations on the passage of ammonia through the mitochondrial membranes and the blood-brain barrier of ammonotelic fishes and fishes with high brain ammonia tolerance, respectively.
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Affiliation(s)
- Yuen K Ip
- Department of Biological Sciences, National University of Singapore Singapore, Republic of Singapore.
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Malca E, Barimo JF, Serafy JE, Walsh PJ. Age and growth of the gulf toadfish Opsanus beta based on otolith increment analysis. JOURNAL OF FISH BIOLOGY 2009; 75:1750-1761. [PMID: 20738646 DOI: 10.1111/j.1095-8649.2009.02426.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
In the present study, sagittal otoliths of confirmed male and female specimens of the gulf toadfish Opsanus beta that were collected monthly over the course of a year from Biscayne Bay, Florida, U.S.A. were analysed. The timing and frequency of O. beta spawning seasons are reported by examination of the gonado-somatic index. The estimated ages of males and females ranged from <1 year to 6 and 5 years, respectively. Strong sexual dimorphism in growth was apparent with von Bertalanffy parameter estimates for males of Linfinity=393.8 mm, K=0.30, t0=0.36 and females of Linfinity=201.1 mm, K=0.79, t0=0.47. Comparison with previously published growth trajectories of the more northerly distributed conspecific Opsanus tau showed that O. beta males had a higher growth rate. Female O. beta and O. tau growth trajectories appear similar, with an indication that the former becomes asymptotic at least a year before the latter. Results are discussed in the context of temperature regimes, reproductive energy allocation and waste urea excretion in the two species.
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Affiliation(s)
- E Malca
- University of Miami, Rosenstiel School of Marine and Atmospheric Science, Cooperative Institute of Marine & Atmospheric Studies, 4600 Rickenbacker Causeway, Miami, FL 33149-1098, USA
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Veauvy CM, Walsh PJ, McDonald MD. Effect of elevated ammonia on tissue nitrogen metabolites in the ureotelic gulf toadfish (Opsanus beta) and the ammoniotelic midshipman (Porichthys notatus). Physiol Biochem Zool 2009; 82:345-52. [PMID: 19072135 DOI: 10.1086/588829] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We investigated possible biochemical pathways explaining extreme ammonia tolerance by the gulf toadfish and specifically tested the prediction that the gulf toadfish Opsanus beta is more tolerant than the plainfin midshipman Porichthys notatus, two confamilial species, because it reverses brain glutamine accumulation during high ammonia exposure. This prediction stems from previous studies demonstrating that gulf toadfish produce urea from glutamine, a pathway not present in the ammoniotelic midshipman. Our results show that at the same water NH(3) concentration, ammonia increases more from control levels in brains of midshipman than toadfish. After 48 h of exposure to 50% of their respective LC(50) (96 h) value for ammonia, toadfish are able to return the ammonia-induced increase in brain glutamine back to control values, reducing brain glutamine by 2,500 micromol kg(-1). However, in midshipman, brain glutamine remains significantly elevated from control throughout the experiment. Toadfish exposed to 33% of their LC(50) (96 h) showed an initial increase in whole body urea, which is then reduced at a rate of 104 micromol kg fish(-1) h(-1) and could be directly excreted into the water. We discuss how the special handling of glutamine in toadfish may explain in part their great tolerance to ammonia.
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Affiliation(s)
- C M Veauvy
- University of Miami, Coral Gables, Florida 33124, USA.
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Rodela TM, Gilmour KM, Walsh PJ, McDonald MD. Cortisol-sensitive urea transport across the gill basolateral membrane of the gulf toadfish (Opsanus beta). Am J Physiol Regul Integr Comp Physiol 2009; 297:R313-22. [DOI: 10.1152/ajpregu.90894.2008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Gulf toadfish ( Opsanus beta) use a unique pulsatile urea excretion mechanism that allows urea to be voided in large pulses via the periodic insertion or activation of a branchial urea transporter. The precise cellular and subcellular location of the facilitated diffusion mechanism(s) remains unclear. An in vitro basolateral membrane vesicle (BLMV) preparation was used to test the hypothesis that urea movement across the gill basolateral membrane occurs through a cortisol-sensitive carrier-mediated mechanism. Toadfish BLMVs demonstrated two components of urea uptake: a linear element at high external urea concentrations, and a phloretin-sensitive saturable constituent ( Km = 0.24 mmol/l; Vmax = 6.95 μmol·mg protein−1·h−1) at low urea concentrations (<1 mmol/l). BLMV urea transport in toadfish was unaffected by in vitro treatment with ouabain, N-ethylmaleimide, or the absence of sodium, conditions that are known to inhibit sodium-coupled and proton-coupled urea transport in vertebrates. Transport kinetics were temperature sensitive with a Q10 > 2, further suggestive of carrier-mediated processes. Our data provide evidence that a basolateral urea facilitated transporter accelerates the movement of urea between the plasma and gills to enable the pulsatile excretion of urea. Furthermore, in vivo infusion of cortisol caused a significant 4.3-fold reduction in BLMV urea transport capacity in lab-crowded fish, suggesting that cortisol inhibits the recruitment of urea transporters to the basolateral membrane, which may ultimately affect the size of the urea pulse event in gulf toadfish.
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Weihrauch D, Wilkie MP, Walsh PJ. Ammonia and urea transporters in gills of fish and aquatic crustaceans. J Exp Biol 2009; 212:1716-30. [PMID: 19448081 DOI: 10.1242/jeb.024851] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The diversity of mechanisms of ammonia and urea excretion by the gills and other epithelia of aquatic organisms, especially fish and crustaceans, has been studied for decades. Although the decades-old dogma of ;aquatic species excrete ammonia' still explains nitrogenous waste excretion for many species, it is clear that there are many mechanistic variations on this theme. Even within species that are ammonoteles, the process is not purely ;passive', often relying on the energizing effects of proton and sodium-potassium ATPases. Within the ammonoteles, Rh (Rhesus) proteins are beginning to emerge as vital ammonia conduits. Many fishes are also known to be capable of substantial synthesis and excretion of urea as a nitrogenous waste. In such species, members of the UT family of urea transporters have been identified as important players in urea transport across the gills. This review attempts to draw together recent information to update the mechanisms of ammonia and urea transport by the gills of aquatic species. Furthermore, we point out several potentially fruitful avenues for further research.
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Affiliation(s)
- Dirk Weihrauch
- Department of Biological Sciences, University of Manitoba, 190 Dysart Road, Winnipeg, MB, R3T 2N2 Canada
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McDonald MD, Vulesevic B, Perry SF, Walsh PJ. Urea transporter and glutamine synthetase regulation and localization in gulf toadfish gill. J Exp Biol 2009; 212:704-12. [PMID: 19218522 DOI: 10.1242/jeb.015875] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
The goal of the present study was to investigate the role of circulating cortisol and urea in the transcriptional regulation of branchial glutamine synthetase (GS), which incorporates NH(3) into glutamate to form glutamine, and the toadfish urea transporter, tUT, which is involved in urea excretion across the gill of the gulf toadfish. GS (of which there are two isoforms, LGS and GGS) and tUT mRNA expression and activity were measured in toadfish exposed to treatments that would induce variable stress responses. In addition, the role of circulating urea in tUT regulation was investigated by infusing toadfish with urea alone or in combination with intraperitoneal injection of RU486, a corticosteroid type II receptor antagonist. There was a 4.8-fold upregulation in the mRNA expression of the gill-specific GS isoform (GGS) in response to cortisol infusion and a similar upregulation in the more ubiquitous isoform (LGS). Furthermore, there was a significant 1.9-fold and 3.3-fold upregulation in the mRNA expression of the toadfish urea transporter, tUT, in response to stress through crowding or exogenous cortisol loading through infusion, respectively. In addition, tUT was found to have a urea-sensitive component to transcriptional regulation that was independent of circulating cortisol concentrations. However, the changes measured in mRNA expression of GGS, LGS and tUT did not correspond with changes in protein activity. To determine the cell type(s) involved in glutamine production and urea excretion, we attempted to localize GGS, LGS and tUT using in situ hybridization. This study is the first to show that GGS and tUT expression appear to occur in gill mitochondria-rich cells of toadfish, suggesting that these cells play a combined glutamine production and urea excretion role, which may have implications for predator avoidance.
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Affiliation(s)
- M Danielle McDonald
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149 USA.
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Phillips K. TOADFISH CLOAKED IN UREA. J Exp Biol 2006. [DOI: 10.1242/jeb.02571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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