02063nas a2200277   4500008004100000245013600041210006900177260001200246300001300258490000600271520117000277100002601447700002601473700002601499700001601525700002101541700002701562700001901589700001901608700002501627700001501652700002101667700002201688700002001710856005501730       2023                        eng d00aPostglacial adaptations enabled colonization and quasi-clonal dispersal of ammonia-oxidizing archaea in modern European large lakes0 aPostglacial adaptations enabled colonization and quasiclonal dis  c02/2023  aeadc93920 v93 a<p>Ammonia-oxidizing archaea (AOA) play a key role in the aquatic nitrogen cycle. Their genetic diversity is viewed as the outcome of evolutionary processes that shaped ancestral transition from terrestrial to marine habitats. However, current genome-wide insights into AOA evolution rarely consider brackish and freshwater representatives or provide their divergence timeline in lacustrine systems. An unbiased global assessment of lacustrine AOA diversity is critical for understanding their origins, dispersal mechanisms, and ecosystem roles. Here, we leveraged continental-scale metagenomics to document that AOA species diversity in freshwater systems is remarkably low compared to marine environments. We show that the uncultured freshwater AOA, &ldquo;<i>Candidatus</i> Nitrosopumilus limneticus,&rdquo; is ubiquitous and genotypically static in various large European lakes where it evolved 13 million years ago. We find that extensive proteome remodeling was a key innovation for freshwater colonization of AOA. These findings reveal the genetic diversity and adaptive mechanisms of a keystone species that has survived clonally in lakes for millennia.</p>1 aNgugi, David, Kamanda1 aSalcher, Michaela, M.1 aAndrei, Adrian-Stefan1 aGhai, Rohit1 aKlotz, Franziska1 aChiriac, Maria-Cecilia1 aIonescu, Danny1 aBüsing, Petra1 aGrossart, Hans-Peter1 aXing, Peng1 aPriscu, John, C.1 aAlymkulov, Salmor1 aPester, Michael  uhttps://www.science.org/doi/10.1126/sciadv.adc939201933nas a2200181   4500008004100000245012100041210006900162260001200231490000600243520129900249100002001548700001901568700002101587700002001608700002501628700002501653856007301678       2017                        eng d00aDiversity and Distribution of Freshwater Aerobic Anoxygenic Phototrophic Bacteria across a Wide Latitudinal Gradient0 aDiversity and Distribution of Freshwater Aerobic Anoxygenic Phot  c02/20170 v83 a<p>Aerobic anoxygenic phototrophs (AAPs) have been shown to exist in numerous marine and brackish environments where they are hypothesized to play important ecological roles. Despite their potential significance, the study of freshwater AAPs is in its infancy and limited to local investigations. Here, we explore the occurrence, diversity and distribution of AAPs in lakes covering a wide latitudinal gradient: Mongolian and German lakes located in temperate regions of Eurasia, tropical Great East African lakes, and polar permanently ice-covered Antarctic lakes. Our results show a widespread distribution of AAPs in lakes with contrasting environmental conditions and confirm that this group is composed of different members of the Alpha- and Betaproteobacteria. While latitude does not seem to strongly influence AAP abundance, clear patterns of community structure and composition along geographic regions were observed as indicated by a strong macro-geographical signal in the taxonomical composition of AAPs. Overall, our results suggest that the distribution patterns of freshwater AAPs are likely driven by a combination of small-scale environmental conditions (specific of each lake and region) and large-scale geographic factors (climatic regions across a latitudinal gradient).</p>1 aFerrera, Isabel1 aSarmento, Hugo1 aPriscu, John, C.1 aChiuchiolo, Amy1 aGonzález, José, M.1 aGrossart, Hans-Peter  uhttp://journal.frontiersin.org/article/10.3389/fmicb.2017.00175/full02077nas a2200181   4500008004100000245016100041210006900202260001200271490000600283520140000289100002601689700002601715700003301741700002001774700002101794700002501815856005501840       2017                        eng d00aEarly diverging lineages within Cryptomycota and Chytridiomycota dominate the fungal communities in ice-covered lakes of the McMurdo Dry Valleys, Antarctica0 aEarly diverging lineages within Cryptomycota and Chytridiomycota  c11/20170 v73 a<p>Antarctic ice-covered lakes are exceptional sites for studying the ecology of aquatic fungi under conditions of minimal human disturbance. In this study, we explored the diversity and community composition of fungi in five permanently covered lake basins located in the Taylor and Miers Valleys of Antarctica. Based on analysis of the 18S rRNA sequences, we showed that fungal taxa represented between 0.93% and 60.32% of the eukaryotic sequences. Cryptomycota and Chytridiomycota dominated the fungal communities in all lakes; however, members of Ascomycota, Basidiomycota, Zygomycota, and Blastocladiomycota were also present. Of the 1313 fungal OTUs identified, the two most abundant, belonging to LKM11 and Chytridiaceae, comprised 74% of the sequences. Significant differences in the community structure were determined among lakes, water depths, habitat features (i.e., brackish vs. freshwaters), and nucleic acids (DNA vs. RNA), suggesting niche differentiation. Network analysis suggested the existence of strong relationships among specific fungal phylotypes as well as between fungi and other eukaryotes. This study sheds light on the biology and ecology of basal fungi in aquatic systems. To our knowledge, this is the first report showing the predominance of early diverging lineages of fungi in pristine limnetic ecosystems, particularly of the enigmatic phylum Cryptomycota.</p>1 aRojas-Jimenez, Keilor1 aWurzbacher, Christian1 aBourne, Elizabeth, Charlotte1 aChiuchiolo, Amy1 aPriscu, John, C.1 aGrossart, Hans-Peter  uhttps://www.nature.com/articles/s41598-017-15598-w