Microbial Survival in an Extreme Martian Analog Ecosystem: Poas Volcano, Costa Rica

Past acid-sulfate hydrothermal systems on Mars have promise in their ability to have hosted life for billions of years. One method for analyzing these systems is to study analog environments on Earth. To assess the astrobiological potential of Martian acid-sulfate hydrothermal systems, the crater lake of the active Po&aacute;s Volcano, Laguna Caliente, was sampled in 2013 and 2017. Laguna Caliente presents an extremely dynamic terrestrial environment with near-ambient to boiling temperatures, pH fluctuations from &minus;0.87 to 1.5, a wide range of chemistries and redox potential, and frequent phreatic-to-phreatomagmatic eruptions. Samples of lake fluid, sulfur clumps, and lake bottom sediment underwent 16S rRNA gene sequencing and metagenomic &ldquo;shotgun&rdquo; sequencing, which revealed this lake hosts an extremely low biodiversity of microorganisms dominated by Acidiphilium spp. Shotgun metagenomics of the samples suggests this community has numerous genetic adaptations that confer survival, including functional pathways to reduce the effects of toxic metals and numerous metabolic pathways utilizing a variety of simple and complex sugar molecules. The identification of these various metabolic pathways suggests adaptations related to carbon limited environments, fulfillment of high energy requirements, and survival in a hostile volcanic setting. The perseverance of life in Laguna Caliente indicates life on Mars could have thrived in analogous environments, stressing the need for the search for life in relict Martian acid-sulfate hydrothermal systems. &nbsp;</p

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Adventive hydrothermal circulation on Stromboli volcano (Aeolian Islands, Italy) revealed by geophysical and geochemical approaches: Implications for general fluid flow models on volcanoes

International audienceOn March 15th 2007 a paroxysmal explosion occurred at the Stromboli volcano. This event generated a large amount of products, mostly lithic blocks, some of which impacted the ground as far as down to 200 m a.s.l., about 1.5 km far away from the active vents. Two days after the explosion, a new vapour emission was discovered on the north-eastern flank of the volcanic edifice, at 560 m a.s.l., just above the area called "Nel Cannestrà". This new vapour emission was due to a block impact. In order to investigate the block impact area to understand the appearance of the vapour emission, we conducted on May 2008 a multidisciplinary study involving Electrical Resistivity Tomography (ERT), Ground Penetrating Radar (GPR), Self-Potential (SP), CO2 soil diffuse degassing and soil temperature surveys. This complementary data set revealed the presence of an anomalous conductive body, probably related to a shallow hydrothermal level, at about 10-15 m depth, more or less parallel to the topography. It is the first time that such a hydrothermal fluid flow, with a temperature close to the water boiling point (76 °C) has been evidenced at Stromboli at this low elevation on the flank of the edifice. The ERT results suggest a possible link between (1) the main central hydrothermal system of Stromboli, located just above the plumbing system feeding the active vents, with a maximum of subsurface soil temperature close to 90 °C and limited by the NeoStromboli summit crater boundary and (2) the investigated area of Nel Cannestrà, at ~ 500 m a.s.l., a buried eruptive fissure active 9 ka ago. In parallel, SP and CO2 soil diffuse degassing measurements suggest in this sector at slightly lower elevation from the block impact crater a magmatic and hydrothermal fluid rising system along the N41° regional fault. A complementary ERT profile, on May 2009, carried out from the NeoStromboli crater boundary down to the block impact crater displayed a flank fluid flow apparently connected to a deeper system. The concept of shallow hydrothermal level have been compared to similar ERT results recently obtained on Mount Etna and La Fossa cone of Vulcano. This information needs to be taken into account in general fluid flow models on volcanoes. In particular, peripheral thermal waters (as those bordering the north-eastern coast of Stromboli) could be contaminated by hydrothermal and magmatic fluids coming from regional faults but also from the summit

Mutation analysis and characterization of ATR sequence variants in breast cancer cases from high-risk French Canadian breast/ovarian cancer families

BACKGROUND: Ataxia telangiectasia-mutated and Rad3-related (ATR) is a member of the PIK-related family which plays, along with ATM, a central role in cell-cycle regulation. ATR has been shown to phosphorylate several tumor suppressors like BRCA1, CHEK1 and TP53. ATR appears as a good candidate breast cancer susceptibility gene and the current study was designed to screen for ATR germline mutations potentially involved in breast cancer predisposition. METHODS: ATR direct sequencing was performed using a fluorescent method while widely available programs were used for linkage disequilibrium (LD), haplotype analyses, and tagging SNP (tSNP) identification. Expression analyses were carried out using real-time PCR. RESULTS: The complete sequence of all exons and flanking intronic sequences were analyzed in DNA samples from 54 individuals affected with breast cancer from non-BRCA1/2 high-risk French Canadian breast/ovarian families. Although no germline mutation has been identified in the coding region, we identified 41 sequence variants, including 16 coding variants, 3 of which are not reported in public databases. SNP haplotypes were established and tSNPs were identified in 73 healthy unrelated French Canadians, providing a valuable tool for further association studies involving the ATR gene, using large cohorts. Our analyses led to the identification of two novel alternative splice transcripts. In contrast to the transcript generated by an alternative splicing site in the intron 41, the one resulting from a deletion of 121 nucleotides in exon 33 is widely expressed, at significant but relatively low levels, in both normal and tumoral cells including normal breast and ovarian tissue. CONCLUSION: Although no deleterious mutations were identified in the ATR gene, the current study provides an haplotype analysis of the ATR gene polymorphisms, which allowed the identification of a set of SNPs that could be used as tSNPs for large-scale association studies. In addition, our study led to the characterization of a novel Δ33 splice form, which could generate a putative truncated protein lacking several functional domains. Additional studies in large cohorts and other populations will be needed to further evaluate if common and/or rare ATR sequence variants can be associated with a modest or intermediate breast cancer risk

Alien Registration- Kearney, Avard B. (Fort Fairfield, Aroostook County)

https://digitalmaine.com/alien_docs/36389/thumbnail.jp

Genetics and Society Project

http://dx.doi.org/10.1159/00005111

Microbial Survival in an Extreme Martian Analog Ecosystem: Poás Volcano, Costa Rica

Past acid-sulfate hydrothermal systems on Mars have promise in their ability to have hosted life for billions of years. One method for analyzing these systems is to study analog environments on Earth. To assess the astrobiological potential of Martian acid-sulfate hydrothermal systems, the crater lake of the active Poás Volcano, Laguna Caliente, was sampled in 2013 and 2017. Laguna Caliente presents an extremely dynamic terrestrial environment with near-ambient to boiling temperatures, pH fluctuations from −0.87 to 1.5, a wide range of chemistries and redox potential, and frequent phreatic-to-phreatomagmatic eruptions. Samples of lake fluid, sulfur clumps, and lake bottom sediment underwent 16S rRNA gene sequencing and metagenomic “shotgun” sequencing, which revealed this lake hosts an extremely low biodiversity of microorganisms dominated by Acidiphilium spp. Shotgun metagenomics of the samples suggests this community has numerous genetic adaptations that confer survival, including functional pathways to reduce the effects of toxic metals and numerous metabolic pathways utilizing a variety of simple and complex sugar molecules. The identification of these various metabolic pathways suggests adaptations related to carbon limited environments, fulfillment of high energy requirements, and survival in a hostile volcanic setting. The perseverance of life in Laguna Caliente indicates life on Mars could have thrived in analogous environments, stressing the need for the search for life in relict Martian acid-sulfate hydrothermal systems.</jats:p