Metagenomic analysis of stress genes in microbial mat commun
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TitleMetagenomic analysis of stress genes in microbial mat communities from Antarctica and the high ArcticAbstractPolar and alpine microbial communities experience a variety of environmental stresses, including perennial cold and freezing; however, knowledge of genomic responses to such conditions is still rudimentary. We analyzed the metagenomes of cyanobacterial mats from Arctic and Antarctic ice shelves, using high-throughput pyrosequencing to test the hypotheses that consortia from these extreme polar habitats were similar in terms of major phyla and subphyla and consequently in their potential responses to environmental stresses. Statistical comparisons of the protein-coding genes showed similarities between the mats from the two poles, with the majority of genes derived from Proteobacteria and Cyanobacteria; however, the relative proportions differed, with cyanobacterial genes more prevalent in the Antarctic mat metagenome. Other differences included a higher representation of Actinobacteria and Alphaproteobacteria in the Arctic metagenomes, which may reflect the greater access to diasporas from both adjacent ice-free lands and the open ocean. Genes coding for functional responses to environmental stress (exopolysaccharides, cold shock proteins, and membrane modifications) were found in all of the metagenomes. However, in keeping with the greater exposure of the Arctic to long-range pollutants, sequences assigned to copper homeostasis genes were statistically (30%) more abundant in the Arctic samples. In contrast, more reads matching the sigma B genes were identified in the Antarctic mat, likely reflecting the more severe osmotic stress during freeze-up of the Antarctic ponds. This study underscores the presence of diverse mechanisms of adaptation to cold and other stresses in polar mats, consistent with the proportional representation of major bacterial groups. â"' 2012, American Society for Microbiology.AcknowledgementsWe thank Ken Dewar for expert guidance in the pyrosequencing and members of the Lovejoy and Vincent laboratory and field teams for scientific and technical assistance. We are grateful to Ian Hawes and Brian Sorrell (NIWA, New Zealand) for sampling on the McMurdo Ice Shelf. We also thank three anonymous reviewers for their time and constructive comments on an earlier version of the manuscript. Polar Shelf Canada provided logistical support. Funding was from the Natural Sciences and Engineering Research Council of Canada (NSERC), with additional support from QuÃ©bec OcÃ©an, the International Polar Year program Microbiological and Ecological Responses to Global Environmental Change in the Polar Regions, the Networks of Centres of Excellence program ArcticNet, Genome Canada, and Genome QuÃ©bec. We thank the staff of Quttinirpaaq National Park. J.C. and W.F.V. acknowledge support from the Canada Research Chair program, and T.V. was supported by a doctoral fellowship from the Canadian Institute of Health Research.
1st AuthorVarin, T.AuthorVarin, T.Lovejoy, C.Jungblut, A.Vincent, W.Corbeil, J.Year2012JournalApplied and Environmental MicrobiologyVolume78Number2Pages549-559DOI10.1128/AEM.06354-11URLhttps://www.scopus.com/inward/recor.....68d7b7dac6fca26db34651025KeywordsActinobacteriaAntarctic ice shelvesAntarcticaCold shockCopper homeostasisCyanobacterial matsEnvironmental stressExopolysaccharidesFreeze-upFunctional responseGenes codingGenomic responseHigh arcticHigh-throughputMembrane modificationMetagenomesMetagenomic analysisMicrobial communitiesOpen oceanOsmotic stressPolar habitatsProtein-coding genesProteobacteriaPyrosequencingStatistical comparisons, Codes (symbols)Microorganisms, Genes, adaptationalpine environmentcoppercyanobacteriumecosystem responseenvironmental stressfunctional changegenetic analysisgenomicshomeostasishypothesis testingice shelfmicrobial communitymicrobial matpolar regionpropaguleprotein, AntarcticaArcticarticlebacteriumbiotaclassificationDNA sequencegeneticsmetagenomemicrobiologysediment, Antarctic RegionsArctic RegionsBacteriaBiotaGeologic SedimentsMetagenomeSequence Analysis, DNA, ActinobacteriaAlphaproteobacteriaBacteria (microorganisms)CyanobacteriaProteobacteria, rank1
TypeArticleCitationVarin, T., Lovejoy, C., Jungblut, A., Vincent, W. and Corbeil, J. (2012) Metagenomic analysis of stress genes in microbial mat communities from Antarctica and the high Arctic. Applied and Environmental Microbiology, 78(2): 549-559 doi:10.1128/AEM.06354-11
Antarctica NZ (26th Nov 2018). Metagenomic analysis of stress genes in microbial mat commun . In Website Antarctica NZ. Retrieved 19th Oct 2021 17:04, from https://adam.antarcticanz.govt.nz/nodes/view/63803