Microbial gene expression during hibernation in arctic ground squirrels: greater differences across gut sections than in response to pre-hibernation dietary protein content
Obligate seasonal hibernators fast for 5–9 months depending on species yet resist muscle atrophy and emerge with little lean mass loss. The role of the gut microbiome in host nitrogen metabolism during hibernation is therefore of considerable interest, and recent studies support a role for urea nitr...
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Online Access: | http://dx.doi.org/10.3389/fgene.2023.1210143 https://www.frontiersin.org/articles/10.3389/fgene.2023.1210143/full |
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crfrontiers:10.3389/fgene.2023.1210143 2024-03-31T07:51:00+00:00 Microbial gene expression during hibernation in arctic ground squirrels: greater differences across gut sections than in response to pre-hibernation dietary protein content Grond, Kirsten Buck, C. Loren Duddleston, Khrystyne N. National Institutes of Health 2023 http://dx.doi.org/10.3389/fgene.2023.1210143 https://www.frontiersin.org/articles/10.3389/fgene.2023.1210143/full unknown Frontiers Media SA https://creativecommons.org/licenses/by/4.0/ Frontiers in Genetics volume 14 ISSN 1664-8021 Genetics (clinical) Genetics Molecular Medicine journal-article 2023 crfrontiers https://doi.org/10.3389/fgene.2023.1210143 2024-03-05T00:04:28Z Obligate seasonal hibernators fast for 5–9 months depending on species yet resist muscle atrophy and emerge with little lean mass loss. The role of the gut microbiome in host nitrogen metabolism during hibernation is therefore of considerable interest, and recent studies support a role for urea nitrogen salvage (UNS) in host-protein conservation. We were interested in the effect of pre-hibernation diet on UNS and the microbial provision of essential amino acids (EAAs) during hibernation; therefore, we conducted a study whereby we fed arctic ground squirrels ( Urocitellus parryii ) pre-hibernation diets containing 9% vs. 18% protein and compared the expression of gut bacterial urease and amino acid (AA) metabolism genes in 4 gut sections (cecum mucosa, cecum lumen, small intestine [SI] mucosa, and SI lumen) during hibernation. We found that pre-hibernation dietary protein content did not affect expression of complete bacterial AA pathway genes during hibernation; however, several individual genes within EAA pathways were differentially expressed in squirrels fed 18% pre-hibernation dietary protein. Expression of genes associated with AA pathways was highest in the SI and lowest in the cecum mucosa. Additionally, the SI was the dominant expression site of AA and urease genes and was distinct from other sections in its overall microbial functional and taxonomic composition. Urease expression in the gut microbiome of hibernating squirrels significantly differed by gut section, but not by pre-hibernation dietary protein content. We identified two individual genes that are part of the urea cycle and involved in arginine biosynthesis, which were significantly more highly expressed in the cecum lumen and SI mucosa of squirrels fed a pre-hibernation diet containing 18% protein. Six bacterial genera were responsible for 99% of urease gene expression: Cupriavidus , Burkholderia , Laribacter , Bradhyrizobium , Helicobacter , and Yersinia. Although we did not find a strong effect of pre-hibernation dietary protein content on ... Article in Journal/Newspaper Arctic Urocitellus parryii Frontiers (Publisher) Arctic Frontiers in Genetics 14 |
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Frontiers (Publisher) |
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unknown |
topic |
Genetics (clinical) Genetics Molecular Medicine |
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Genetics (clinical) Genetics Molecular Medicine Grond, Kirsten Buck, C. Loren Duddleston, Khrystyne N. Microbial gene expression during hibernation in arctic ground squirrels: greater differences across gut sections than in response to pre-hibernation dietary protein content |
topic_facet |
Genetics (clinical) Genetics Molecular Medicine |
description |
Obligate seasonal hibernators fast for 5–9 months depending on species yet resist muscle atrophy and emerge with little lean mass loss. The role of the gut microbiome in host nitrogen metabolism during hibernation is therefore of considerable interest, and recent studies support a role for urea nitrogen salvage (UNS) in host-protein conservation. We were interested in the effect of pre-hibernation diet on UNS and the microbial provision of essential amino acids (EAAs) during hibernation; therefore, we conducted a study whereby we fed arctic ground squirrels ( Urocitellus parryii ) pre-hibernation diets containing 9% vs. 18% protein and compared the expression of gut bacterial urease and amino acid (AA) metabolism genes in 4 gut sections (cecum mucosa, cecum lumen, small intestine [SI] mucosa, and SI lumen) during hibernation. We found that pre-hibernation dietary protein content did not affect expression of complete bacterial AA pathway genes during hibernation; however, several individual genes within EAA pathways were differentially expressed in squirrels fed 18% pre-hibernation dietary protein. Expression of genes associated with AA pathways was highest in the SI and lowest in the cecum mucosa. Additionally, the SI was the dominant expression site of AA and urease genes and was distinct from other sections in its overall microbial functional and taxonomic composition. Urease expression in the gut microbiome of hibernating squirrels significantly differed by gut section, but not by pre-hibernation dietary protein content. We identified two individual genes that are part of the urea cycle and involved in arginine biosynthesis, which were significantly more highly expressed in the cecum lumen and SI mucosa of squirrels fed a pre-hibernation diet containing 18% protein. Six bacterial genera were responsible for 99% of urease gene expression: Cupriavidus , Burkholderia , Laribacter , Bradhyrizobium , Helicobacter , and Yersinia. Although we did not find a strong effect of pre-hibernation dietary protein content on ... |
author2 |
National Institutes of Health |
format |
Article in Journal/Newspaper |
author |
Grond, Kirsten Buck, C. Loren Duddleston, Khrystyne N. |
author_facet |
Grond, Kirsten Buck, C. Loren Duddleston, Khrystyne N. |
author_sort |
Grond, Kirsten |
title |
Microbial gene expression during hibernation in arctic ground squirrels: greater differences across gut sections than in response to pre-hibernation dietary protein content |
title_short |
Microbial gene expression during hibernation in arctic ground squirrels: greater differences across gut sections than in response to pre-hibernation dietary protein content |
title_full |
Microbial gene expression during hibernation in arctic ground squirrels: greater differences across gut sections than in response to pre-hibernation dietary protein content |
title_fullStr |
Microbial gene expression during hibernation in arctic ground squirrels: greater differences across gut sections than in response to pre-hibernation dietary protein content |
title_full_unstemmed |
Microbial gene expression during hibernation in arctic ground squirrels: greater differences across gut sections than in response to pre-hibernation dietary protein content |
title_sort |
microbial gene expression during hibernation in arctic ground squirrels: greater differences across gut sections than in response to pre-hibernation dietary protein content |
publisher |
Frontiers Media SA |
publishDate |
2023 |
url |
http://dx.doi.org/10.3389/fgene.2023.1210143 https://www.frontiersin.org/articles/10.3389/fgene.2023.1210143/full |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Urocitellus parryii |
genre_facet |
Arctic Urocitellus parryii |
op_source |
Frontiers in Genetics volume 14 ISSN 1664-8021 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3389/fgene.2023.1210143 |
container_title |
Frontiers in Genetics |
container_volume |
14 |
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1795029494527950848 |