Diversité des virus dans les lacs de fonte de pergélisol au nord du Québec
Arctic regions are undergoing rapid changes due to global warming. Permafrost thawing and erosion is accelerating, creating small and shallow lakes, called thermokarst lakes, that are now widespread in Arctic landscapes. Thaw lakes can be classified in two groups depending on the landscape (palsa, l...
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fttriple:oai:gotriple.eu:http://hdl.handle.net/20.500.11794/29807 2023-05-15T15:02:06+02:00 Diversité des virus dans les lacs de fonte de pergélisol au nord du Québec Diversity of viruses in permafrost melting lakes in northern Quebec Lévesque, Alice Culley, Alexander Vincent, Warwick F. Arctique 2018-01-01 https://hdl.handle.net/20.500.11794/29807 fr fre Université Laval http://hdl.handle.net/20.500.11794/29807 other CorpusUL geo envir Thesis https://vocabularies.coar-repositories.org/resource_types/c_46ec/ 2018 fttriple https://doi.org/20.500.11794/29807 2023-01-22T18:21:37Z Arctic regions are undergoing rapid changes due to global warming. Permafrost thawing and erosion is accelerating, creating small and shallow lakes, called thermokarst lakes, that are now widespread in Arctic landscapes. Thaw lakes can be classified in two groups depending on the landscape (palsa, lithalsa), and this has a great impact on their limnological properties. These freshwater ecosystems are highly stratified and harbour microbial assemblages that are important contributors of greenhouse gases to the atmosphere. In general, the two major groups involved in the top-down control of microbial populations are either grazers or viruses. Here, we focused our study on viral communities, as it is now widely recognized that viruses are key components in all aquatic ecosystems. Although they have a large impact on nutrient cycles and host evolution and dynamics, viruses in high latitudes freshwater ecosystems remain poorly characterized. The aims of this study were: (1) to determine viral diversity in different types of thermokarst lakes by targeting specific families of viruses; and (2) to isolate a cyanophage from a subarctic lake. Using a PCR-based approach followed by high-throughput sequencing, we characterized the viral community composition in contrasting subarctic waterbodies. Comparisons suggested that viral diversity was primarily influenced by landscape type, which affects the host communities. Also, we isolated and sequenced the genome of two novel cyanomyoviruses. Analysis of these genomes revealed the presence of two auxiliary metabolic genes, suggesting horizontal gene transfer events between viruses and hosts. Overall, this study sheds light into the dynamics and the composition of viral communities in high-latitude freshwater environments. Les mares et lacs de fonte de pergélisol (ou lac de thermokarst) sont désormais parmi les écosystèmes d’eau douce les plus communs en région arctique. Il existe deux types de lac de thermokarst en fonction de la composition du sol dans lequel celui-ci se ... Thesis Arctic Arctique* Global warming palsa permafrost Subarctic Thermokarst pergélisol Unknown Arctic |
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geo envir Lévesque, Alice Diversité des virus dans les lacs de fonte de pergélisol au nord du Québec |
topic_facet |
geo envir |
description |
Arctic regions are undergoing rapid changes due to global warming. Permafrost thawing and erosion is accelerating, creating small and shallow lakes, called thermokarst lakes, that are now widespread in Arctic landscapes. Thaw lakes can be classified in two groups depending on the landscape (palsa, lithalsa), and this has a great impact on their limnological properties. These freshwater ecosystems are highly stratified and harbour microbial assemblages that are important contributors of greenhouse gases to the atmosphere. In general, the two major groups involved in the top-down control of microbial populations are either grazers or viruses. Here, we focused our study on viral communities, as it is now widely recognized that viruses are key components in all aquatic ecosystems. Although they have a large impact on nutrient cycles and host evolution and dynamics, viruses in high latitudes freshwater ecosystems remain poorly characterized. The aims of this study were: (1) to determine viral diversity in different types of thermokarst lakes by targeting specific families of viruses; and (2) to isolate a cyanophage from a subarctic lake. Using a PCR-based approach followed by high-throughput sequencing, we characterized the viral community composition in contrasting subarctic waterbodies. Comparisons suggested that viral diversity was primarily influenced by landscape type, which affects the host communities. Also, we isolated and sequenced the genome of two novel cyanomyoviruses. Analysis of these genomes revealed the presence of two auxiliary metabolic genes, suggesting horizontal gene transfer events between viruses and hosts. Overall, this study sheds light into the dynamics and the composition of viral communities in high-latitude freshwater environments. Les mares et lacs de fonte de pergélisol (ou lac de thermokarst) sont désormais parmi les écosystèmes d’eau douce les plus communs en région arctique. Il existe deux types de lac de thermokarst en fonction de la composition du sol dans lequel celui-ci se ... |
author2 |
Culley, Alexander Vincent, Warwick F. |
format |
Thesis |
author |
Lévesque, Alice |
author_facet |
Lévesque, Alice |
author_sort |
Lévesque, Alice |
title |
Diversité des virus dans les lacs de fonte de pergélisol au nord du Québec |
title_short |
Diversité des virus dans les lacs de fonte de pergélisol au nord du Québec |
title_full |
Diversité des virus dans les lacs de fonte de pergélisol au nord du Québec |
title_fullStr |
Diversité des virus dans les lacs de fonte de pergélisol au nord du Québec |
title_full_unstemmed |
Diversité des virus dans les lacs de fonte de pergélisol au nord du Québec |
title_sort |
diversité des virus dans les lacs de fonte de pergélisol au nord du québec |
publisher |
Université Laval |
publishDate |
2018 |
url |
https://hdl.handle.net/20.500.11794/29807 |
op_coverage |
Arctique |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Arctique* Global warming palsa permafrost Subarctic Thermokarst pergélisol |
genre_facet |
Arctic Arctique* Global warming palsa permafrost Subarctic Thermokarst pergélisol |
op_source |
CorpusUL |
op_relation |
http://hdl.handle.net/20.500.11794/29807 |
op_rights |
other |
op_doi |
https://doi.org/20.500.11794/29807 |
_version_ |
1766334087282294784 |