Genetic adaptations of marine invertebrates to hydrothermal vent habitats.

Hydrothermal vents are unique habitats like an oases of life compared with typical deep-sea, soft-sediment environments. Most animals that live in these habitats are invertebrates, and they have adapted to extreme vent environments that include high temperatures, hypoxia, high sulfide, high metal concentration, and darkness. The advent of next-generation sequencing technology, especially the coming of the new era of omics, allowed more studies to focus on the molecular adaptation of these invertebrates to vent habitats. Many genes linked to hydrothermal adaptation have been studied. We summarize the findings related to these genetic adaptations and discuss which new techniques can facilitate studies in the future.

Double-Sided Pressure-Sensitive Adhesive Materials under Human-Centric Extreme Environments.

Maintaining the adhesion strength of flexible pressure-sensitive adhesives (PSAs) is crucial for advanced applications, such as health monitoring. Sustainable mounting is critical for wearable sensor devices, especially under challenging surroundings such as low and high temperatures (e.g., polar regions or deserts), underwater and sweat environments (physical activity), and cyclical shear complex stresses. In this article, we consider the adhesive, mechanical, and optical properties of medical-grade double-sided PSAs by simulating extreme human-centric environments. Diverse temperature conditions, water and humidity exposures, and cyclical loads were selected and tested over long intervals, up to 28 days. We observed that high temperatures increased the shear adhesion strength due to the pore closing and expanding contact area between the adhesive layer and substrate. Conversely, low temperatures caused the adhesive layers to harden and reduce the adhesive strength. Immersion in salty and weakly acidic water and excessive humidity reduced adhesion as water interfered with the interfacial interactions. PSA films showed either adhesive or cohesive failure under extreme mechanical stresses and cyclical loading, which is also affected by the presence of various polar solvents. We demonstrated that the variable adhesive performance, mechanical properties, and optical transparency of pressure-sensitive materials can be directly related to changes in their morphologies, surface roughness, swelling state, and alternation of the mechanical contact area, helping to establish the broader rules of design for wearable human health monitoring sensors for the long-term application of wearable devices, sensors, and electrodes.

The influence of extended fasting on thyroid hormone: local and differentiated regulatory mechanisms.

The hypometabolism induced by fasting has great potential in maintaining health and improving survival in extreme environments, among which thyroid hormone (TH) plays an important role in the adaptation and the formation of new energy metabolism homeostasis during long-term fasting. In the present review, we emphasize the potential of long-term fasting to improve physical health and emergency rescue in extreme environments, introduce the concept and pattern of fasting and its impact on the body's energy metabolism consumption. Prolonged fasting has more application potential in emergency rescue in special environments. The changes of THs caused by fasting, including serum biochemical characteristics, responsiveness of the peripheral and central hypothalamus-pituitary-thyroid (HPT) axis, and differential changes of TH metabolism, are emphasized in particular. It was proposed that the variability between brain and liver tissues in THs uptake, deiodination activation and inactivation is the key regulatory mechanism for the cause of peripheral THs decline and central homeostasis. While hypothalamic tanycytes play a pivotal role in the fine regulation of the HPT negative feedback regulation during long-term fasting. The study progress of tanycytes on thyrotropin-releasing hormone (TRH) release and deiodination is described in detail. In conclusion, the combination of the decrease of TH metabolism in peripheral tissues and stability in the central HPT axis maintains the basal physiological requirement and new energy metabolism homeostasis to adapt to long-term food scarcity. The molecular mechanisms of this localized and differential regulation will be a key research direction for developing measures for hypometabolic applications in extreme environment.

Wet-dry or freeze-thaw alternation can regulate the impacts of farmland plastic pollution on soil bacterial communities and functions.

The persistence of farmland plastic pollution has raised significant concerns regarding its potential long-term impacts on soil health in the context of global climate change. However, there are still gaps in the understanding of the impacts of plastic residues on soil microbial communities and functions in agricultural environments under unstable and extreme climatic conditions. In this study, the effects of plastic residues (two types and three shapes) on farmland soil bacterial communities and functions across varying environmental conditions were investigated through microscopic experiments. The results revealed that plastic residues subjected to wet-dry or freeze-thaw alternations exhibited greater degradation compared to those under natural conditions. The effects of plastic residue types and shapes on soil bacterial diversity and function were regulated by environmental factors. The plastic residues significantly reduced the stability of the bacterial network under natural condition (P < 0.05), whereas the opposite phenomenon was observed under wet-dry or freeze-thaw alternating conditions. Compared to under natural condition, lower numbers of bacterial functional pathways exhibiting significant differences due to plastic residues were observed under wet-dry or freeze-thaw alternating conditions. Significant associations were observed between soil bacterial communities and functions and various soil physicochemical properties under natural conditions (P < 0.05), and most of these associations were attenuated in the wet-dry or freeze-thaw alternations. This study demonstrated the potential impacts of plastic pollution on farmland soil microbiomes, which could be modulated by both residue characteristics and climatic conditions. Specifically, extreme environments could mitigate plastic-pollution-driven influences on soil microbiomes.

Genomic Functional Analysis of Novel Radiation-Resistant Species of Knollia sp. nov. S7-12T from the North Slope of Mount Everest.

Radiation protection is an important field of study, as it relates to human health and environmental safety. Radiation-resistance mechanisms in extremophiles are a research hotspot, as this knowledge has great application value in bioremediation and development of anti-radiation drugs. Mount Everest, an extreme environment of high radiation exposure, harbors many bacterial strains resistant to radiation. However, owing to the difficulties in studying them because of the extreme terrain, many remain unexplored. In this study, a novel species (herein, S7-12T) was isolated from the moraine of Mount Everest, and its morphology and functional and genomic characteristics were analyzed. The strain S7-12T is white in color, smooth and rounded, non-spore-forming, and non-motile and can survive at a UV intensity of 1000 J/m2, showing that it is twice as resistant to radiation as Deinococcus radiodurans. Radiation-resistance genes, including IbpA and those from the rec and CspA gene families, were identified. The polyphasic taxonomic approach revealed that the strain S7-12T (=KCTC 59114T =GDMCC 1.3458T) is a new species of the genus Knoellia and is thus proposed to be named glaciei. The in-depth study of the genome of strain S7-12T will enable us to gain further insights into its potential use in radiation resistance. Understanding how microorganisms resist radiation damage could reveal potential biomarkers and therapeutic targets, leading to the discovery of potent anti-radiation compounds, thereby improving human resistance to the threat of radiation.

Whole-genome resequencing identifies candidate genes associated with heat adaptation in chickens.

The wide distribution and diverse varieties of chickens make them important models for studying genetic adaptation. The aim of this study was to identify genes that alter heat adaptation in commercial chicken breeds by comparing genetic differences between tropical and cold-resistant chickens. We analyzed whole-genome resequencing data of 186 chickens across various regions in Asia, including the following breeds: Bian chickens (B), Dagu chickens (DG), Beijing-You chickens (BY), and Gallus gallus jabouillei from China; Gallus gallus murghi from India; Vietnam native chickens (VN); Thailand native chickens (TN) and Gallus gallus spadiceus from Thailand; and Indonesia native chickens (IN), Gallus gallus gallus, and Gallus gallus bankiva from Indonesia. In total, 5,454,765 SNPs were identified for further analyses. Population genetic structure analysis revealed that each local chicken breed had undergone independent evolution. Additionally, when K = 5, B, BY, and DG chickens shared a common ancestor and exhibited high levels of inbreeding, suggesting that northern cold-resistant chickens are likely the result of artificial selection. In contrast, the runs of homozygosity (ROH) and the ROH-based genomic inbreeding coefficient (FROH) results for IN, TN, and VN chickens showed low levels of inbreeding. Low population differentiation index values indicated low differentiation levels, suggesting low genetic diversity in tropical chickens, implying increased vulnerability to environmental changes, decreased adaptability, and disease resistance. Whole-genome selection sweep analysis revealed 69 candidate genes, including LGR4, G6PC, and NBR1, between tropical and cold-resistant chickens. The genes were further subjected to GO and KEGG enrichment analyses, revealing that most of the genes were primarily enriched in biological synthesis processes, metabolic processes, central nervous system development, ion transmembrane transport, and the Wnt signaling pathway. Our study identified heat adaptation genes and their functions in chickens that primarily affect chickens in high-temperature environments through metabolic pathways. These heat-resistance genes provide a theoretical basis for improving the heat-adaptation capacity of commercial chicken breeds.

Phylogenetic and morphological re-evaluation of Camptophora.

The genetic variety and habitats of Camptophora species, generally known as black yeast, have not been clarified. In this study, we re-evaluated Camptophora based on morphological observations and phylogenetic analyses. Because prior investigations on Camptophora only included a few strains/specimens, 24 Camptophora-related strains were newly obtained from 13 leaf samples of various plant species to redefine the genetic and species concepts of Camptophora. Their molecular phylogenetic relationships were examined using small subunit nuclear ribosomal DNA (nSSU, 18S rDNA), the internal transcribed spacer (ITS) rDNA operon, the large subunit nuclear ribosomal DNA (LSU, 28S rDNA), ß-tubulin, the second largest subunit of RNA polymerase II (rpb2), and mitochondrial small subunit DNA (mtSSU). Single- and multi-locus analyses using nSSU-ITS-LSU-rpb2-mtSSU revealed a robust phylogenetic relationship among Camptophora species within Chaetothyriaceae. Camptophora species could be distinguished from other chaetothyriaceous genera by their snake-shaped conidia with microcyclic conidiation and loosely interwoven mycelial masses. Based on the results of phylogenetic analyses, two undescribed lineages were recognized, and Ca. schimae was excluded from the genus. ITS sequence comparison with environmental DNA sequences revealed that the distribution of the genus is restricted to the Asia-Pacific region. Camptophora has been isolated or detected from abrupt sources, and this was attributed to its microcycle. The mechanisms driving genetic diversity within species are discussed with respect to their phyllosphere habitats.

Unveiling Hidden Hyperuniformity: Radial Turing Pattern Formation of Marangoni-Driven SiO2 Nanoparticles on Liquid Metal Surface.

Mastering the self-organization of nanoparticle morphologies is pivotal in soft matter physics and film growth. Silicon dioxide (SiO2) nanoparticles are an archetypical model of nanomotor in soft matter. Here, the emphasis is on the self-organizing behavior of SiO2 nanoparticles under extreme conditions. It is unveiled that manipulating the states of the metal substrate profoundly dictates the motion characteristics of SiO2 nanoparticles. This manipulation triggers the emergence of intricate morphologies and distinctive patterns. Employing a reaction-diffusion model, the fundamental roles played by Brownian motion and Marangoni-driven motion in shaping fractal structures and radial Turing patterns are demonstrated, respectively. Notably, these radial Turing patterns showcase hyperuniform order, challenging conventional notions of film morphology. These discoveries pave the way for crafting non-equilibrium morphological materials, poised with the potential for self-healing, adaptability, and innovative applications.

Mortality of mesozooplankton in an acidified ocean: Investigating the impact of shallow hydrothermal vents across multiple monsoonal periods.

The shallow hydrothermal vents (HVs) of Kueishan Island are considered as a template for studying the extremes of sulfide-polluted and acidified water. The present study examined the biological and spatiotemporal aspects of mesozooplankton mortality in waters around this extreme HV environment. Zooplankton sample collection was carried out in three monsoonal periods and the results revealed that there was a significant decrease in the mortality of total mesozooplankton with increasing distance from the HVs. The overall mortality of mesozooplankton showed a significant negative correlation with sea surface temperature and pH. Particularly, mortality of copepods showed a significant negative correlation with pH, whereas it was significantly positive correlated with sea surface temperature in the southwest monsoon prevailing period. Overall, the results may imply a situation that zooplankton will encounter in the more acidified environment of a future ocean.

When people start getting real: The Group Living Skills Survey for extreme work environments.

Introduction: Group living skills (GLS), that is, being tidy and considerate of others, are an important skillset for teams who live and work together. However, this construct does not have a validated measure to enable an understanding of how group living skills influence team dynamics over time. We developed and validated a short measure of group living skills for teams living in extreme work environments. Methods: We collected data from 83 individuals in 24 teams living and working in space and spaceflight analog environments on missions of 45-240 days. Results: We provide evidence of reliability and validity for the GLS Survey over time and identify a two-factor structure. We also demonstrate its use as a measure of team-level dynamics and its utility as a sociometric measure to identify a person's degree of group living skills. Discussion: We outline recommendations for using this new measure in future research and applied settings to understand this unique aspect of teams living and working together.

Decomposition in an extreme cold environment and associated microbiome-prediction model implications for the postmortem interval estimation.

Introduction: The accurate estimation of postmortem interval (PMI), the time between death and discovery of the body, is crucial in forensic science investigations as it impacts legal outcomes. PMI estimation in extremely cold environments becomes susceptible to errors and misinterpretations, especially with prolonged PMIs. This study addresses the lack of data on decomposition in extreme cold by providing the first overview of decomposition in such settings. Moreover, it proposes the first postmortem microbiome prediction model for PMI estimation in cold environments, applicable even when the visual decomposition is halted. Methods: The experiment was conducted on animal models in the second-coldest region in the United States, Grand Forks, North Dakota, and covered 23 weeks, including the winter months with temperatures as low as -39°C. Random Forest analysis models were developed to estimate the PMI based either uniquely on 16s rRNA gene microbial data derived from nasal swabs or based on both microbial data and measurable environmental parameters such as snow depth and outdoor temperatures, on a total of 393 samples. Results: Among the six developed models, the best performing one was the complex model based on both internal and external swabs. It achieved a Mean Absolute Error (MAE) of 1.36 weeks and an R2 value of 0.91. On the other hand, the worst performing model was the minimal one that relied solely on external swabs. It had an MAE of 2.89 weeks and an R2 of 0.73. Furthermore, among the six developed models, the commonly identified predictors across at least five out of six models included the following genera: Psychrobacter (ASV1925 and ASV1929), Carnobacterium (ASV2872) and Pseudomonas (ASV1863). Discussion: The outcome of this research provides the first microbial model able to predict PMI with an accuracy of 9.52 days over a six-month period of extreme winter conditions.

History of Diversification and Adaptation from North to South Revealed by Genomic Data: Guanacos from the Desert to Sub-Antarctica.

The increased availability of quality genomic data has greatly improved the scope and resolution of our understanding of the recent evolutionary history of wild species adapted to extreme environments and their susceptibility to anthropogenic impacts. The guanaco (Lama guanicoe), the largest wild ungulate in South America, is a good example. The guanaco is well adapted to a wide range of habitats, including the Sechura Desert, the high Andes Mountains to the north, and the extreme temperatures and conditions of Navarino Island to the south. Guanacos also have a long history of overexploitation by humans. To assess the evolutionary impact of these challenging habitats on the genomic diversity, we analyzed 38 genomes (∼10 to 16×) throughout their extensive latitudinal distribution from the Sechura and Atacama Desert to southward into Tierra del Fuego Island. These included analyses of patterns of unique differentiation in the north and geographic region further south with admixture among L. g. cacsilensis and L. g. guanicoe. Our findings provide new insights on the divergence of the subspecies ∼800,000 yr BP and document two divergent demographic trajectories and to the initial expansion of guanaco into the more southern portions of the Atacama Desert. Patagonian guanacos have experienced contemporary reductions in effective population sizes, likely the consequence of anthropogenic impacts. The lowest levels of genetic diversity corresponded to their northern and western limits of distribution and some varying degrees of genetic differentiation. Adaptive genomic diversity was strongly linked with environmental variables and was linked with colonization toward the south followed by adaptation.

Genome-wide analysis to uncover how Pocillopora acuta survives the challenging intertidal environment.

Characterisation of genomic variation among corals can help uncover variants underlying trait differences and contribute towards genotype prioritisation in coastal restoration projects. For example, there is growing interest in identifying resilient genotypes for transplantation, and to better understand the genetic processes that allow some individuals to survive in specific conditions better than others. The coral species Pocillopora acuta is known to survive in a wide range of habitats, from reefs artificial coastal defences, suggesting its potential use as a starter species for ecological engineering efforts involving coral transplantation onto intertidal seawalls. However, the intertidal section of coastal armour is a challenging environment for corals, with conditions during periods of emersion being particularly stressful. Here, we scanned the entire genome of P. acuta corals to identify the regions harbouring single nucleotide polymorphisms (SNPs) and copy number variations (CNVs) that separate intertidal colonies (n = 18) from those found in subtidal areas (n = 21). Findings revealed 74,391 high quality SNPs distributed across 386 regions of the P. acuta genome. While the majority of the detected SNPs were in non-coding regions, 12% were identified in exons (i.e. coding regions). Functional SNPs that were significantly associated with intertidal colonies were found in overrepresented genomic regions linked to cellular homeostasis, metabolism, and signalling processes, which may represent local environmental adaptation in the intertidal. Interestingly, regions that exhibited CNVs were also associated with metabolic and signalling processes, suggesting P. acuta corals living in the intertidal have a high capacity to perform biological functions critical for survival in extreme environments.

Challenges and Breakthroughs in Enhancing Temperature Tolerance of Sodium-Ion Batteries.

Lithium-based batteries (LBBs) have been highly researched and recognized as a mature electrochemical energy storage (EES) system in recent years. However, their stability and effectiveness are primarily confined to room temperature conditions. At temperatures significantly below 0 °C or above 60 °C, LBBs experience substantial performance degradation. Under such challenging extreme contexts, sodium-ion batteries (SIBs) emerge as a promising complementary technology, distinguished by their fast dynamics at low-temperature regions and superior safety under elevated temperatures. Notably, developing SIBs suitable for wide-temperature usage still presents significant challenges, particularly for specific applications such as electric vehicles, renewable energy storage, and deep-space/polar explorations, which requires a thorough understanding of how SIBs perform under different temperature conditions. By reviewing the development of wide-temperature SIBs, the influence of temperature on the parameters related to battery performance, such as reaction constant, charge transfer resistance, etc., is systematically and comprehensively analyzed. The review emphasizes challenges encountered by SIBs in both low and high temperatures while exploring recent advancements in SIB materials, specifically focusing on strategies to enhance battery performance across diverse temperature ranges. Overall, insights gained from these studies will drive the development of SIBs that can handle the challenges posed by diverse and harsh climates.

Exploring perceptions of extreme environments and extremophiles in Chilean schoolchildren: an ethnographic study.

Chile is unique because of its diverse extreme environment, ranging from arid climates in the north to polar climates in Patagonia. Microorganisms that live in these environments are called extremophiles, and these habitats experience intense ecosystem changes owing to climate warming. Most studies of extremophiles have focused on their biotechnological potential; however, no study has examined how students describe extremophiles. Therefore, we were interested in answering the following question: How do schoolchildren living in extreme environments describe their environments and extremophiles? We performed an ethnographic study and analyzed the results of 347 representative drawings of participants aged 12-16 years from three schools located in the extreme environments of Chile San Pedro de Atacama (hyper-arid, 2,400 m), Lonquimay (forest, 925 m), and Punta Arenas (sub-Antarctic, 34 m). The social representation approach was used to collect data, and systemic networks were used to organize and systematize the drawings. The study found that, despite differences between extreme environments, certain natural elements, such as trees and the sun, are consistently represented by schoolchildren. The analysis revealed that the urban and rural categories were the two main categories identified. The main systemic networks were rural-sun (21,1%) for hyper-arid areas, urban-tree (14,1%) for forest areas, and urban-furniture (23,4%) for sub-Antarctic areas. When the results were analyzed by sex, we found a statistically significant difference for the rural category in the 7th grade, where girls mentioned being more rural than boys. Students living in hyper-arid areas represented higher extremophile drawings, with 57 extremophiles versus 20 and 39 for students living in sub-Antarctic and forest areas, respectively. Bacteria were extremophiles that were more represented. The results provide evidence that natural variables and semantic features that allow an environment to be categorized as extreme are not represented by children when they are focused on and inspired by the environment in which they live, suggesting that school literacy processes impact representations of their environment because they replicate school textbooks and not necessarily their environment.

Exploring the prokaryote-eukaryote interplay in microbial mats from an Andean athalassohaline wetland.

Microbial community assembly results from the interaction between biotic and abiotic factors. However, environmental selection is thought to predominantly shape communities in extreme ecosystems. Salar de Huasco, situated in the high-altitude Andean Altiplano, represents a poly-extreme ecosystem displaying spatial gradients of physicochemical conditions. To disentangle the influence of abiotic and biotic factors, we studied prokaryotic and eukaryotic communities from microbial mats and underlying sediments across contrasting areas of this athalassohaline ecosystem. The prokaryotic communities were primarily composed of bacteria, notably including a significant proportion of photosynthetic organisms like Cyanobacteria and anoxygenic photosynthetic members of Alpha- and Gammaproteobacteria and Chloroflexi. Additionally, Bacteroidetes, Verrucomicrobia, and Deltaproteobacteria were abundantly represented. Among eukaryotes, photosynthetic organisms (Ochrophyta and Archaeplastida) were predominant, alongside relatively abundant ciliates, cercozoans, and flagellated fungi. Salinity emerged as a key driver for the assembly of prokaryotic communities. Collectively, abiotic factors influenced both prokaryotic and eukaryotic communities, particularly those of algae. However, prokaryotic communities strongly correlated with photosynthetic eukaryotes, suggesting a pivotal role of biotic interactions in shaping these communities. Co-occurrence networks suggested potential interactions between different organisms, such as diatoms with specific photosynthetic and heterotrophic bacteria or with protist predators, indicating influences beyond environmental selection. While some associations may be explained by environmental preferences, the robust biotic correlations, alongside insights from other ecosystems and experimental studies, suggest that symbiotic and trophic interactions significantly shape microbial mat and sediment microbial communities in this athalassohaline ecosystem.IMPORTANCEHow biotic and abiotic factors influence microbial community assembly is still poorly defined. Here, we explore their influence on prokaryotic and eukaryotic community assembly within microbial mats and sediments of an Andean high-altitude polyextreme wetland system. We show that, in addition to abiotic elements, mutual interactions exist between prokaryotic and eukaryotic communities. Notably, photosynthetic eukaryotes exhibit a strong correlation with prokaryotic communities, specifically diatoms with certain bacteria and other protists. Our findings underscore the significance of biotic interactions in community assembly and emphasize the necessity of considering the complete microbial community.

Unveiling microbial guilds and symbiotic relationships in Antarctic sponge microbiomes.

Marine sponges host diverse microbial communities. Although we know many of its ecological patterns, a deeper understanding of the polar sponge holobiont is still needed. We combine high-throughput sequencing of ribosomal genes, including the largest taxonomic repertoire of Antarctic sponge species analyzed to date, functional metagenomics, and metagenome-assembled genomes (MAGs). Our findings show that sponges harbor more exclusive bacterial and archaeal communities than seawater, while microbial eukaryotes are mostly shared. Furthermore, bacteria in Antarctic sponge holobionts establish more cooperative interactions than in sponge holobionts from other environments. The bacterial classes that established more positive relations were Bacteroidia, Gamma- and Alphaproteobacteria. Antarctic sponge microbiomes contain microbial guilds that encompass ammonia-oxidizing archaea, ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, and sulfur-oxidizing bacteria. The retrieved MAGs showed a high level of novelty and streamlining signals and belong to the most abundant members of the main microbial guilds in the Antarctic sponge holobiont. Moreover, the genomes of these symbiotic bacteria contain highly abundant functions related to their adaptation to the cold environment, vitamin production, and symbiotic lifestyle, helping the holobiont survive in this extreme environment.

Lipid-based paleoecological and biogeochemical reconstruction of Store Saltsø, an extreme lacustrine system in SW Greenland.

Polar lakes harbour a unique biogeochemistry that reflects the implications of climatic fluctuations against a susceptible yet extreme environment. In addition to polar, Store Saltsø (Kangerlussuaq, southwestern Greenland) is an endorheic lake with alkaline and oligotrophic waters that host a distinctive ecology adapted to live in such particular physico-chemical and environmental conditions. By exploring the sedimentary record of Store Saltsø at a molecular and compound-specific isotopic level, we were able to understand its ecology and biogeochemical evolution upon climate change. We employed lipid biomarkers to identify biological sources and metabolic traits in different environmental samples (shore terrace, sediment core, and white precipitates at the shore), and their succession over time to reconstruct the lake paleobiology. Different molecular ratios and geochemical proxies provided further insights toward the evolution of environmental conditions in the frame of the deglaciation history of Kangerlussuaq. The relative abundance of terrestrial (i.e., plant derived) biomarkers (odd long-chain n-alkanes, even long-chain n-alkanols, and phytosterols) in the upper half of the shore terrace versus the relatively more present aquatic biomarkers (botryococcenes and long-chain alkenones) in its lower half revealed higher lake water levels in the past. Moreover, the virtual absence of organics in the deepest section of the sediment core (32-29 cm depth) suggested that the lake did not yet exist at the northwestern shore of Store Saltsø ∼5100 years ago. According to the relative abundance of lipid biomarkers detected in the adjacent section above (29-25 cm depth), we hypothesize that the northwestern shore of Store Saltsø formed ∼4900 years ago. By combining the molecular and compound-specific isotopic analysis of lipids in a ∼360 cm sedimentary sequence, we recreated the paleobiology and evolution of an extreme lacustrine environment suitable for the study of the limits of life and the effects of climate warming.

Genomics of Yoonia sp. Isolates (Family Roseobacteraceae) from Lake Zhangnai on the Tibetan Plateau.

Understanding the genomic differentiation between marine and non-marine aquatic microbes remains a compelling question in ecology. While previous research has identified several lacustrine lineages within the predominantly marine Roseobacteraceae family, limited genomic data have constrained our understanding of their ecological adaptation mechanisms. In this study, we isolated four novel Yoonia strains from a brackish lake on the Tibetan Plateau. These strains have diverged from their marine counterparts within the same genus, indicating a recent habitat transition event from marine to non-marine environments. Metabolic comparisons and ancestral genomic reconstructions in a phylogenetic framework reveal metabolic shifts in salinity adaptation, compound transport, aromatics degradation, DNA repair, and restriction systems. These findings not only corroborate the metabolic changes commonly observed in other non-marine Roseobacters but also unveil unique adaptations, likely reflecting the localized metabolic changes in responses to Tibetan Plateau environments. Collectively, our study expands the known genomic diversity of non-marine Roseobacteraceae lineages and enhances our understanding of microbial adaptations to lacustrine ecosystems.