Search

Euryarchaeal lineages have been believed to have a methanogenic last common ancestor. However, members of euryarchaeal Archaeoglobi have long been considered nonmethanogenic and their evolutionary history remains elusive. Here, three high-quality metagenomic-assembled genomes (MAGs) retrieved from high-temperature oil reservoir and hot springs, together with three newly assembled Archaeoglobi MAGs from previously reported hot spring metagenomes, are demonstrated to represent a novel genus of Archaeoglobaceae, "Candidatus Methanomixophus." All "Ca Methanomixophus" MAGs encode an M methyltransferase (MTR) complex and a traditional type of methyl-coenzyme M reductase (MCR) complex, which is different from the divergent MCR complexes found in "Ca Polytropus marinifundus." In addition, "Ca Methanomixophus dualitatem" MAGs preserve the genomic capacity for dissimilatory sulfate reduction. Comparative phylogenetic analysis supports a laterally transferred origin for an MCR complex and vertical heritage of the MTR complex in this lineage. Metatranscriptomic analysis revealed concomitant in situ activity of hydrogen-dependent methylotrophic methanogenesis and heterotrophic fermentation within populations of "Ca Methanomixophus hydrogenotrophicum" in a high-temperature oil reservoir.IMPORTANCE Current understanding of the diversity, biology, and ecology of Archaea is very limited, especially considering how few of the known phyla have been cultured or genomically explored. The reconstruction of "Ca Methanomixophus" MAGs not only expands the known range of metabolic versatility of the members of Archaeoglobi but also suggests that the phylogenetic distribution of MCR and MTR complexes is even wider than previously anticipated.

How often, and in what contexts, have archaeologists discussed racism over the last four decades? Do societal events lead to sustained discussions of racism among the academic community? Here, the authors seek to answer these questions by applying computational text analysis methods to 68 176 abstracts from 41 meetings of the Society for American Archaeology. Discussions of racism are found to be rare--usually a passing mention in the context of broader social issues. Historical archaeologists have addressed racism more frequently than other archaeologists. The results form a baseline against which the discipline's engagement with racism as a research theme and with anti-racist strategies might be tracked. Keywords: computational text analysis, racism, academic discourse, Society for American Archaeology, history of archaeology, Introduction On 25 May 2020, George Floyd was killed by police in Minneapolis, Minnesota. Scenes of a White police officer kneeling on a Black man's neck ignited widespread protests, not [...]

Previous studies of acetate-promoted bioremediation of uranium-contaminated aquifers focused on Geobacter because no other microorganisms that can couple the oxidation of acetate with U(VI) reduction had been detected in situ. Monitoring the levels of methyl CoM reductase subunit A (mcrA) transcripts during an acetate-injection field experiment demonstrated that acetoclastic methanogens from the genus Methanosarcina were enriched after 40 days of acetate amendment. The increased abundance of Methanosarcina corresponded with an accumulation of methane in the groundwater. In order to determine whether Methanosarcina species could be participating in U(VI) reduction in the subsurface, cell suspensions of Methanosarcina barkeri were incubated in the presence of U(VI) with acetate provided as the electron donor. U(VI) was reduced by metabolically active M. barkeri cells; however, no U(VI) reduction was observed in inactive controls. These results demonstrate that Methanosarcina species could play an important role in the long-term bioremediation of uranium-contaminated aquifers after depletion of Fe(III) oxides limits the growth of Geobacter species. The results also suggest that Methanosarcina have the potential to influence uranium geochemistry in a diversity of anaerobic sedimentary environments.

SUMMARY: The sex of dioecious plants is mainly determined by genetic factors, but it can also be converted by environmental cues such as exogenous phytohormones. Gibberellic acids (GAs) are well‐known inducers of flowering and sexual development, yet the pathway of gibberellin‐induced sex conversion in dioecious spinach (Spinacia oleracea L.) remains elusive. Based on sex detection before and after GA3 application using T11A and SSR19 molecular markers, we confirmed and elevated the masculinization effect of GA on a single female plant through exogenous applications of GA3, showing complete conversion and functional stamens. Silencing of GIBBERELLIC ACID INSENSITIVE (SpGAI), a single DELLA family protein that is a central GA signaling repressor, results in similar masculinization. We also show that SpGAI can physically interact with the spinach KNOX transcription factor SHOOT MERISTEMLESS (SpSTM), which is a homolog of the flower meristem identity regulator STM in Arabidopsis. The silencing of SpSTM also masculinized female flowers in spinach. Furthermore, SpSTM could directly bind the intron of SpPI to repress SpPI expression in developing female flowers. Overall, our results suggest that GA induces a female masculinization process through the SpGAI‐SpSTM‐SpPI regulatory module in spinach. These insights may help to clarify the molecular mechanism underlying the sex conversion system in dioecious plants while also elucidating the physiological basis for the generation of unisexual flowers so as to establish dioecy in plants. Significance Statement: Using environmental factors such as hormones to induce sex conversion is an important approach to studying dioecy sex differentiation, which is a special character closely related to flowering, reproduction, and fruiting. In our research, exogenous GA3 can induce functional masculinization of individual spinach, and the GA‐regulating pathway was established: GA‐SpGAI‐SpSTM‐SpPI. This study provides new ideas and theoretical support for studying the sex differentiation mechanisms of spinach and other dioecious plants. [ABSTRACT FROM AUTHOR]

In order to study the effects of body color and social familiarity on the shoal selection in cichlids, Sciaenochromis fryeri with a blue body color, was selected as the study object. White Hindongo socolofi and yellow Labidochromis caeruleus were chosen as stimuli to test whether experimental fish displayed a preference for specific color phenotypes, considering the controlled social familiarity of the shoal. Additionally, the study aimed to determine if experimental fish exhibited a preference for associating with shoal stimuli possessing a preferred color phenotype but were unfamiliar to the shoal. The results showed that when there was no difference in the social familiarity of shoal stimuli, both individuals and groups demonstrated a preference for associating with shoals of the preferred color phenotype. However, when stimulating fish with different social familiarity, individual S. fryeri showed an association with the more socially familiar shoal, while group experimental fish displayed a preference for the shoal with the preferred color shoal phenotype. The study show that body color exerts a greater influence on shoal selection than social familiarity. Body color emerges as a potentially significant shoal cue for cichlids, providing a foundation for exploring the ecological effects of body color (such as predator-prey interactions) within fish shoals. [ABSTRACT FROM AUTHOR]

Magic-angle spinning (MAS) rotor, a device for high-speed spinning of solid samples, is an essential component of the probes used in solid-state nuclear magnetic resonance (NMR) experiments. In this study, a 4 mm MAS rotor was designed and fabricated in-house. Fluid-solid coupling simulation was carried out to compute the stress and strain in the MAS rotor. Modal analysis was performed to determine the various modes and critical speeds of the MAS rotor. Actual spinning speed test and MAS NMR sampling were carried out to test the performance of the rotor. The results showed that the MAS rotor built in-house could operate normally at a spinning speed up to 14 kHz. The 1H NMR signals of adamantane collected at 4 kHz and 12.5 kHz were collected and compared. These results demonstrated that the 4 mm MAS rotor built in-house could meet the requirements of conventional solid-state NMR experiments.

Triggered by a fascinating publication in the New England Journal of Medicine detailing China's new multi-pronged strategy to control and eventually interrupt the transmission of Schistosoma japonicum, this PLoS Neglected Tropical Diseases Debate critically examines the generalizability and financial costs of the studies presented from the marshlands of the lake region. Edmund Seto from the University of California and colleagues emphasize that the epidemiology and control of schistosomiasis varies according to the social-ecological context. They conjecture that the successful intervention packages piloted in the lake region is not fully fit for the hilly and mountainous environments in Sichuan and Yunnan provinces, and hence call for more flexible, setting-specific, and less expensive control strategies. In response, Xiao-Nong Zhou from the National Institute of Parasitic Diseases at the Chinese Center of Disease Control and Prevention and colleagues explain the steps from designing pilot studies to the articulation and implementation of a new national control strategy through a careful process of scaling-up and adaptations. Finally, the two opponents converge. The need for integrated, intersectoral, and setting-specific control measures is stressed, supported by rigorous surveillance and continuous research. Experiences and lessons from China are important for shaping the schistosomiasis elimination agenda.