Alkaline guts contribute to immunity during exposure to acidified seawater in the sea urchin larva
Larval stages of members of the Abulacraria superphylum including echinoderms and hemichordates have highly alkaline midguts. To date, the reason for the evolution of such extreme pH conditions in the gut of these organisms remains unknown. Here, we test the hypothesis that, analogous to the acidic...
Published in: | Journal of Experimental Biology |
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fthighwire:oai:open-archive.highwire.org:jexbio:223/9/jeb222844 2023-05-15T17:50:44+02:00 Alkaline guts contribute to immunity during exposure to acidified seawater in the sea urchin larva Stumpp, Meike Petersen, Inga Thoben, Femke Yan, Jia-Jiun Leippe, Matthias Hu, Marian Y. 2020-05-13 00:31:15.0 text/html http://jeb.biologists.org/cgi/content/short/223/9/jeb222844 https://doi.org/10.1242/jeb.222844 en eng The Company of Biologists Ltd http://jeb.biologists.org/cgi/content/short/223/9/jeb222844 http://dx.doi.org/10.1242/jeb.222844 Copyright (C) 2020, Company of Biologists RESEARCH ARTICLE TEXT 2020 fthighwire https://doi.org/10.1242/jeb.222844 2020-05-19T07:35:26Z Larval stages of members of the Abulacraria superphylum including echinoderms and hemichordates have highly alkaline midguts. To date, the reason for the evolution of such extreme pH conditions in the gut of these organisms remains unknown. Here, we test the hypothesis that, analogous to the acidic stomachs of vertebrates, these alkaline conditions may represent a first defensive barrier to protect from environmental pathogens. pH-optimum curves for five different species of marine bacteria demonstrated a rapid decrease in proliferation rates by 50–60% between pH 8.5 and 9.5. Using the marine bacterium Vibrio diazotrophicus , which elicits a coordinated immune response in the larvae of the sea urchin Strongylocentrotus purpuratus , we studied the physiological responses of the midgut pH regulatory machinery to this pathogen. Gastroscopic microelectrode measurements demonstrate a stimulation of midgut alkalization upon infection with V. diazotrophicus accompanied by an upregulation of acid–base transporter transcripts of the midgut. Pharmacological inhibition of midgut alkalization resulted in an increased mortality rate of larvae during Vibrio infection. Reductions in seawater pH resembling ocean acidification conditions lead to moderate reductions in midgut alkalization. However, these reductions in midgut pH do not affect the immune response or resilience of sea urchin larvae to a Vibrio infection under ocean acidification conditions. Our study addressed the evolutionary benefits of the alkaline midgut of Ambulacraria larval stages. The data indicate that alkaline conditions in the gut may serve as a first defensive barrier against environmental pathogens and that this mechanism can compensate for changes in seawater pH. Text Ocean acidification HighWire Press (Stanford University) Journal of Experimental Biology |
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English |
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RESEARCH ARTICLE |
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RESEARCH ARTICLE Stumpp, Meike Petersen, Inga Thoben, Femke Yan, Jia-Jiun Leippe, Matthias Hu, Marian Y. Alkaline guts contribute to immunity during exposure to acidified seawater in the sea urchin larva |
topic_facet |
RESEARCH ARTICLE |
description |
Larval stages of members of the Abulacraria superphylum including echinoderms and hemichordates have highly alkaline midguts. To date, the reason for the evolution of such extreme pH conditions in the gut of these organisms remains unknown. Here, we test the hypothesis that, analogous to the acidic stomachs of vertebrates, these alkaline conditions may represent a first defensive barrier to protect from environmental pathogens. pH-optimum curves for five different species of marine bacteria demonstrated a rapid decrease in proliferation rates by 50–60% between pH 8.5 and 9.5. Using the marine bacterium Vibrio diazotrophicus , which elicits a coordinated immune response in the larvae of the sea urchin Strongylocentrotus purpuratus , we studied the physiological responses of the midgut pH regulatory machinery to this pathogen. Gastroscopic microelectrode measurements demonstrate a stimulation of midgut alkalization upon infection with V. diazotrophicus accompanied by an upregulation of acid–base transporter transcripts of the midgut. Pharmacological inhibition of midgut alkalization resulted in an increased mortality rate of larvae during Vibrio infection. Reductions in seawater pH resembling ocean acidification conditions lead to moderate reductions in midgut alkalization. However, these reductions in midgut pH do not affect the immune response or resilience of sea urchin larvae to a Vibrio infection under ocean acidification conditions. Our study addressed the evolutionary benefits of the alkaline midgut of Ambulacraria larval stages. The data indicate that alkaline conditions in the gut may serve as a first defensive barrier against environmental pathogens and that this mechanism can compensate for changes in seawater pH. |
format |
Text |
author |
Stumpp, Meike Petersen, Inga Thoben, Femke Yan, Jia-Jiun Leippe, Matthias Hu, Marian Y. |
author_facet |
Stumpp, Meike Petersen, Inga Thoben, Femke Yan, Jia-Jiun Leippe, Matthias Hu, Marian Y. |
author_sort |
Stumpp, Meike |
title |
Alkaline guts contribute to immunity during exposure to acidified seawater in the sea urchin larva |
title_short |
Alkaline guts contribute to immunity during exposure to acidified seawater in the sea urchin larva |
title_full |
Alkaline guts contribute to immunity during exposure to acidified seawater in the sea urchin larva |
title_fullStr |
Alkaline guts contribute to immunity during exposure to acidified seawater in the sea urchin larva |
title_full_unstemmed |
Alkaline guts contribute to immunity during exposure to acidified seawater in the sea urchin larva |
title_sort |
alkaline guts contribute to immunity during exposure to acidified seawater in the sea urchin larva |
publisher |
The Company of Biologists Ltd |
publishDate |
2020 |
url |
http://jeb.biologists.org/cgi/content/short/223/9/jeb222844 https://doi.org/10.1242/jeb.222844 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
http://jeb.biologists.org/cgi/content/short/223/9/jeb222844 http://dx.doi.org/10.1242/jeb.222844 |
op_rights |
Copyright (C) 2020, Company of Biologists |
op_doi |
https://doi.org/10.1242/jeb.222844 |
container_title |
Journal of Experimental Biology |
_version_ |
1766157617901600768 |