Multiple adaptations to polar and alpine environments within cyanobacteria: a phylogenomic and Bayesian approach

Abstract

Citation:Chrismas NAM, Anesio AM and Sánchez-Baracaldo P (2015) Multiple adaptations to polar and alpine environments within cyanobacteria : a phylogenomic and Bayesian approach. Front. Microbiol. 6:1070. doi: 10.3389/fmicb.2015.01070 Multiple adaptations to polar and alpine environments within cyanobacteria: a phylogenomic and Bayesian approach Cyanobacteria are major primary producers in the polar and alpine regions contributing significantly to nitrogen and carbon cycles in the cryosphere. Recent advancements in environmental sequencing techniques have revealed great molecular diversity of microorganisms in cold environments. However, there are no comprehensive phylogenetic analyses including the entire known diversity of cyanobacteria from these extreme environments. We present here a global phylogenetic analysis of cyanobacteria including an extensive dataset comprised of available small subunit (SSU) rRNA gene sequences of cyanobacteria from polar and high altitude environments. Furthermore, we used a large-scale multi-gene (135 proteins and 2 ribosomal RNAs) genome constraint including 57 cyanobacterial genomes. Our analyses produced the first phylogeny of cold cyanobacteria exhibiting robust deep branching relationships implementing a phylogenomic approach. We recovered several clades common to Arctic, Antarctic and alpine sites suggesting that the traits necessary for survival in the cold have been acquired by a range of different mechanisms in all major cyanobacteria lineages. Bayesian ancestral state reconstruction revealed that 20 clades each have common ancestors with high probabilities of being capable of surviving in cold environments.

Pole-to-Pole Connections: Similarities between Arctic and Antarctic Microbiomes and Their Vulnerability to Environmental Change

“…We conclude that the microbiota of both polar regions may be more connected than previously assumed and our data suggest a biogeographical connection between both poles, consistent with some previous studies Jungblut et al, 2010;Chrismas et al, 2015;Cox et al, 2016;Biersma et al, 2017;Mohit et al, 2017). The polar microbial communities in our study are an assemblage of ubiquitously-distributed and potentially endemic taxa.…”

“…In fact, large differences in temperature and annual solar radiation but not regional precipitation explained community differences in the present dataset. A broad scale phylogenetic meta-analysis recently suggested the presence of cold-tolerant cyanobacteria in all cyanobacterial taxonomic clades (Chrismas et al, 2015). The latter is also reflected in our dataset, in which bacterial species and strains surviving in polar environments belong to cosmopolitan groups at higher taxonomic levels.…”

Aliterella atlantica gen. nov., sp. nov., and Aliterella antarctica sp. nov., novel members of coccoid Cyanobacteria

“…However, this notion has not always been found to be true, as several unicellular Cyanobacteria have a larger genome size than multicellular Cyanobacteria (Larsson et al, 2011;Shih et al, 2013). Multicellularity arises as a result of the incomplete separation of daughter cells after cell division, and the behaviour of cells within multicellular structures is coordinated by both shared and unique molecular mechanisms (Rossetti et al, 2010;Claessen et al, 2014). It has been shown that mutations of the cell wall amiC2 gene in the filamentous heterocytous strain Nostoc punctiforme ATCC 29133, encoding an amidase involved in septa formation, induced colonial unicellular morphology in this cyanobacterium, and prevented heterocyte differentiation (Lehner et al, 2011).…”

“…cell morphology) does not reflect their evolution and the strength of relationships among taxa, which is the basis of modern systematics (Honda et al, 1999;Robertson et al, 2001;Kim et al, 2014;Kom arek et al, 2014). Moreover, advancements in cyanobacterial genome sequencing have enabled large-scale multi-gene phylogenetic analyses that have provided a robust framework to solve deep-branching relationships and help to elucidate the evolutionary history of these phototrophic bacteria (S anchez-Baracaldo et al, 2005;Blank & S anchezBaracaldo, 2010;Larsson et al, 2011;Shih et al, 2013;Bombar et al, 2014;Calteau et al, 2014;Chrismas et al, 2015;Schirrmeister et al, 2015). So far, there are approximately 300 cyanobacterial genomes available in public databases among complete, draft and incomplete genomes, which represent less than 1% of the total bacterial genomes sequenced (https://gold.jgi-psf.org/index, accessed on December 9, 2015).…”

Future directions and priorities for Arctic bryophyte research

“…Moreover, we do not know the extent to which plants and their microbiomes will respond in concert or the ecosystem consequences of asymmetries in their movement due to either plants and microbes experiencing different selective pressures or different capacities for migration. At the broad scale, the biogeography of polar cyanobacteria shows similar trends to polar bryophytes, with a number of lineages displaying widespread distributions across polar and montane regions (Jungblut et al 2010;Chrismas et al 2015), suggesting similar processes. At a finer scale, however, distinct microbiome community compositions along fire and glacial disturbance gradients in boreal and sub-Antarctic ecosystems, respectively, suggest that selective pressures and colonization patterns will differ between host mosses and their microbiomes (Arróniz-Crespo et al 2014;Cutler et al 2016).…”