The Experts below are selected from a list of 873 Experts worldwide ranked by ideXlab platform
Sigitas Radzevicius - One of the best experts on this subject based on the ideXlab platform.
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the role of temporal abundance structure and habitat preferences in the survival of conodonts during the mid early silurian ireviken mass extinction event
PLOS ONE, 2015Co-Authors: Andrej Spiridonov, Antanas Brazauskas, Sigitas RadzeviciusAbstract:The Ireviken event was one of the most intense extinction episodes that occurred during the mid-Paleozoic Era. It had a strong global effect on a range of clades, with conodonts, graptolites and chitinozoans affected most. Using geophysical proxies and conodont species parameters of their temporal abundance structure we investigate how they affected the selectivity of conodont species survival during this calamity. After performing bivariate logistic analyses on 34 species of conodonts, we find three variables that were statistically significantly associated with their odds of survival. These namely include spectral exponents that describe degrees of autocorrelation in a time series, the skewness of species abundance distribution, and avErage environmental preferences, which are mostly determined by ancient water depths at sampling sites. Model selection of multivariate logistic models found the best model includes species local abundance skewness and substrate preference. A similar pattern is revealed through the regression tree analysis. The apparent extinction selectivity points to a possible causes of environmental deterioration during the Ireviken event. The significant positive relationship between extinction risk and preferential existence in deeper environments suggests the open ocean causal mechanisms of biotic stress that occurred during the Ireviken event. Marine regressions, which were previously suggested as a causal factor in this extinction episode, on theoretical grounds should have had higher impact on species living in near-shore environments, through the processes of habitat loss which are associated with decreases of shelfal areas. In addition, the significant positive correlations found between skewness of abundance distributions and spectral exponent values and the probability of species survival suggest that community and ecosystem processes (which controlled species abundance fluctuation patterns) were significantly related to selectivity processes of this smaller mass extinction event.
Jie Cui - One of the best experts on this subject based on the ideXlab platform.
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multiple infiltration and cross species transmission of foamy viruses across the Paleozoic to the cenozoic Era
Journal of Virology, 2021Co-Authors: Yicong Chen, Y Zhang, Xiaoman Wei, Jie CuiAbstract:Foamy viruses (FVs) are complex retroviruses that can infect humans and other animals. In this study, by integrating transcriptomic and genomic data, we discovered 412 FVs from 6 lineages in amphibians, which significantly increased the known set of FVs in amphibians. Among these lineages, salamander FVs maintained a coevolutionary pattern with their hosts that could be dated back to the Paleozoic Era, while in contrast, frog FVs were much more likely acquired from cross-species (class-level) transmission in the Cenozoic Era. In addition, we found that three distinct FV lineages had integrated into the genome of a salamander. Unexpectedly, we identified a lineage of endogenous FVs in caecilians that expressed all complete major genes, demonstrating the potential existence of an exogenous form of FV outside of mammals. Our discovery of rare phenomena in amphibian FVs has significantly increased our understanding of the macroevolution of the complex retrovirus. IMPORTANCE Foamy viruses (FVs) represent, more so than other viruses, the best model of coevolution between a virus and a host. This study represents the largest investigation so far of amphibian FVs and reveals 412 FVs of 6 distinct lineages from three major orders of amphibians. Besides a coevolutionary pattern, cross-species and repeated infections were also observed during the evolution of amphibian FVs. Remarkably, expressed FVs including a potential exogenous form were discovered, suggesting that active FVs might be underestimated in nature. These findings revealed that the multiple origins and complex evolution of amphibian FVs started from the Paleozoic Era.
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multiple infiltration and cross species transmission of foamy viruses across Paleozoic to cenozoic Era
bioRxiv, 2020Co-Authors: Yicong Chen, Y Zhang, Xiaoman Wei, Jie CuiAbstract:Abstract Foamy viruses (FVs) are complex retroviruses that can infect humans and other animals. In this study, by integrating transcriptomic and genomic data, we discovered 412 FVs from 6 lineages in amphibians, which significantly increased the known set of FVs in amphibians. Among these lineages, salamander FVs maintained a co-evolutionary pattern with their hosts that could be dated back to the Paleozoic Era, while, on the contrary, frog FVs were much more likely acquired from cross-species (class level) transmission in the Cenozoic Era. In addition, we found three distinct FV lineages had integrated into the genome of a salamander. Unexpectedly, we identified a potential exogenous form of FV circulated in caecilian, demonstrating the existence of exogenous form of FV besides mammals. Our discovery of rare phenomena in amphibian FVs has overturned our collective understanding of the macroevolution of the complex retrovirus. Importance Foamy viruses (FVs) represent, more so than other viruses, the best model of co-evolution between a virus and a host. This study represents so far, the largest investigation of amphibian FVs and revealed 412 FVs of 6 distinct lineages from three major orders of amphibians. Besides co-evolutionary pattern, cross-species and repeated infection were also observed during evolution of amphibian FVs. Remarkably, expressed FVs including a potential exogenous form were discovered, suggesting live FVs could be underestimated in nature. These findings revealed the multiple origin and complex evolution of amphibian FVs started from the Paleozoic Era.
Lisa M. Gahagan - One of the best experts on this subject based on the ideXlab platform.
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Paleozoic laurentia gondwana intEraction and the origin of the appalachian andean mountain system
Geological Society of America Bulletin, 1994Co-Authors: Ian W. D. Dalziel, Luis Hugo Dalla Salda, Lisa M. GahaganAbstract:Laurentia, the rift-bounded Precambrian nucleus of North America, may have broken out from a Neoproterozoic supercontinent between East and West Gondwana. SevEral lines of evidence suggest that the Appalachian margin of Laurentia subsequently collided with the proto-Andean margin of the amalgamated Gondwana supercontinent in different relative positions during early and mid-Paleozoic time, in route to final docking against northwest Africa to complete the assembly of Pangea. Hence the Appalachian and Andean orogens may have originated as a single mountain system. The ovErall hypothesis retains the same paleomagnetic and paleobiogeographic controls as previous global reconstructions for the Paleozoic Era. Laurentia-Gondwana collisions may help to explain contemporaneous unconformities in the Paleozoic sedimentary cover of the Laurentian, Gondwanan, and Baltic cratons.
Andrej Spiridonov - One of the best experts on this subject based on the ideXlab platform.
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the role of temporal abundance structure and habitat preferences in the survival of conodonts during the mid early silurian ireviken mass extinction event
PLOS ONE, 2015Co-Authors: Andrej Spiridonov, Antanas Brazauskas, Sigitas RadzeviciusAbstract:The Ireviken event was one of the most intense extinction episodes that occurred during the mid-Paleozoic Era. It had a strong global effect on a range of clades, with conodonts, graptolites and chitinozoans affected most. Using geophysical proxies and conodont species parameters of their temporal abundance structure we investigate how they affected the selectivity of conodont species survival during this calamity. After performing bivariate logistic analyses on 34 species of conodonts, we find three variables that were statistically significantly associated with their odds of survival. These namely include spectral exponents that describe degrees of autocorrelation in a time series, the skewness of species abundance distribution, and avErage environmental preferences, which are mostly determined by ancient water depths at sampling sites. Model selection of multivariate logistic models found the best model includes species local abundance skewness and substrate preference. A similar pattern is revealed through the regression tree analysis. The apparent extinction selectivity points to a possible causes of environmental deterioration during the Ireviken event. The significant positive relationship between extinction risk and preferential existence in deeper environments suggests the open ocean causal mechanisms of biotic stress that occurred during the Ireviken event. Marine regressions, which were previously suggested as a causal factor in this extinction episode, on theoretical grounds should have had higher impact on species living in near-shore environments, through the processes of habitat loss which are associated with decreases of shelfal areas. In addition, the significant positive correlations found between skewness of abundance distributions and spectral exponent values and the probability of species survival suggest that community and ecosystem processes (which controlled species abundance fluctuation patterns) were significantly related to selectivity processes of this smaller mass extinction event.
Bernard Henrissat - One of the best experts on this subject based on the ideXlab platform.
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an ancient family of lytic polysaccharide monooxygenases with roles in arthropod development and biomass digestion
Nature Communications, 2018Co-Authors: Federico Sabbadin, Glyn R. Hemsworth, Luisa Ciano, Bernard Henrissat, Paul Dupree, Theodora Tryfona, Rita D. S. Marques, Sean T. SweeneyAbstract:Thermobia domestica belongs to an ancient group of insects and has a remarkable ability to digest crystalline cellulose without microbial assistance. By investigating the digestive proteome of Thermobia, we have identified over 20 members of an uncharacterized family of lytic polysaccharide monooxygenases (LPMOs). We show that this LPMO family spans across sevEral clades of the Tree of Life, is of ancient origin, and was recruited by early arthropods with possible roles in remodeling endogenous chitin scaffolds during development and metamorphosis. Based on our in-depth characterization of Thermobia’s LPMOs, we propose that diversification of these enzymes toward cellulose digestion might have endowed ancestral insects with an effective biochemical apparatus for biomass degradation, allowing the early colonization of land during the Paleozoic Era. The vital role of LPMOs in modern agricultural pests and disease vectors offers new opportunities to help tackle global challenges in food security and the control of infectious diseases.