Coastal fishes have a fundamental role in marine ecosystem functioning and contributions to people, but face increasing threats due to climate change, habitat degradation and overexploitation. The extent to which human pressures are impacting coastal fish biodiversity in comparison with geographic and environmental factors at large spatial scale is still under scrutiny. Here, we took advantage of environmental DNA (eDNA) metabarcoding to investigate the relationship between fish biodiversity, including taxonomic and genetic components, and environmental but also socio-economic factors.
Location
Tropical, temperate and polar coastal areas.
Time period
Present day.
Major taxa studied
Marine fishes.
Methods
We analysed fish eDNA in 263 stations (samples) in 68 sites distributed across polar, temperate and tropical regions. We modelled the effect of environmental, geographic and socio-economic factors on α- and β-diversity. We then computed the partial effect of each factor on several fish biodiversity components using taxonomic molecular units (MOTU) and genetic sequences. We also investigated the relationship between fish genetic α- and β-diversity measured from our barcodes, and phylogenetic but also functional diversity.
Results
We show that fish eDNA MOTU and sequence α- and β-diversity have the strongest correlation with environmental factors on coastal ecosystems worldwide. However, our models also reveal a negative correlation between biodiversity and human dependence on marine ecosystems. In areas with high dependence, diversity of all fish, cryptobenthic fish and large fish MOTUs declined steeply. Finally, we show that a sequence diversity index, accounting for genetic distance between pairs of MOTUs, within and between communities, is a reliable proxy of phylogenetic and functional diversity.
Main conclusions
Together, our results demonstrate that short eDNA sequences can be used to assess climate and direct human impacts on marine biodiversity at large scale in the Anthropocene and can further be extended to investigate biodiversity in its phylogenetic and functional dimensions. 相似文献
Zanthoxylum armatum and Zanthoxylum bungeanum, known as ‘Chinese pepper’, are distinguished by their extraordinary complex genomes, phenotypic innovation of adaptive evolution and species-special metabolites. Here, we report reference-grade genomes of Z. armatum and Z. bungeanum. Using high coverage sequence data and comprehensive assembly strategies, we derived 66 pseudochromosomes comprising 33 homologous phased groups of two subgenomes, including autotetraploid Z. armatum. The genomic rearrangements and two whole-genome duplications created large (~4.5 Gb) complex genomes with a high ratio of repetitive sequences (>82%) and high chromosome number (2n = 4x = 132). Further analysis of the high-quality genomes shed lights on the genomic basis of involutional reproduction, allomones biosynthesis and adaptive evolution in Chinese pepper, revealing a high consistent relationship between genomic evolution, environmental factors and phenotypic innovation. Our study provides genomic resources and new insights for investigating diversification and phenotypic innovation in Chinese pepper, with broader implications for the protection of plants under severe environmental changes. 相似文献
Cardiomyopathy is a progressive disease of the myocardium leading to impaired contractility. Genotoxic cancer therapies are known to be potent drivers of cardiomyopathy, whereas causes of spontaneous disease remain unclear. To test the hypothesis that endogenous genotoxic stress contributes to cardiomyopathy, we deleted the DNA repair gene Ercc1 specifically in striated muscle using a floxed allele of Ercc1 and mice expressing Cre under control of the muscle-specific creatinine kinase (Ckmm) promoter or depleted systemically (Ercc1−/D mice). Ckmm-Cre+/−;Ercc1−/fl mice expired suddenly of heart disease by 7 months of age. As young adults, the hearts of Ckmm-Cre+/−;Ercc1−/fl mice were structurally and functionally normal, but by 6-months-of-age, there was significant ventricular dilation, wall thinning, interstitial fibrosis, and systolic dysfunction indicative of dilated cardiomyopathy. Cardiac tissue from the tissue-specific or systemic model showed increased apoptosis and cardiac myocytes from Ckmm-Cre+/-;Ercc1−/fl mice were hypersensitive to genotoxins, resulting in apoptosis. p53 levels and target gene expression, including several antioxidants, were increased in cardiac tissue from Ckmm-Cre+/−;Ercc1−/fl and Ercc1−/D mice. Despite this, cardiac tissue from older mutant mice showed evidence of increased oxidative stress. Genetic or pharmacologic inhibition of p53 attenuated apoptosis and improved disease markers. Similarly, overexpression of mitochondrial-targeted catalase improved disease markers. Together, these data support the conclusion that DNA damage produced endogenously can drive cardiac disease and does so mechanistically via chronic activation of p53 and increased oxidative stress, driving cardiac myocyte apoptosis, dilated cardiomyopathy, and sudden death. 相似文献
Elevated arginases including type-I (Arg-I) and type-II isoenzyme (Arg-II) are reported to play a role in aging, age-associated organ inflammaging, and fibrosis. A role of arginase in pulmonary aging and underlying mechanisms are not explored. Our present study shows increased Arg-II levels in aging lung of female mice, which is detected in bronchial ciliated epithelium, club cells, alveolar type 2 (AT2) pneumocytes, and fibroblasts (but not vascular endothelial and smooth muscle cells). Similar cellular localization of Arg-II is also observed in human lung biopsies. The age-associated increase in lung fibrosis and inflammatory cytokines, including IL-1β and TGF-β1 that are highly expressed in bronchial epithelium, AT2 cells, and fibroblasts, are ameliorated in arg-ii deficient (arg-ii−/−) mice. The effects of arg-ii−/− on lung inflammaging are weaker in male as compared to female animals. Conditioned medium (CM) from human Arg-II-positive bronchial and alveolar epithelial cells, but not that from arg-ii−/− cells, activates fibroblasts to produce various cytokines including TGF-β1 and collagen, which is abolished by IL-1β receptor antagonist or TGF-β type I receptor blocker. Conversely, TGF-β1 or IL-1β also increases Arg-II expression. In the mouse models, we confirmed the age-associated increase in IL-1β and TGF-β1 in epithelial cells and activation of fibroblasts, which is inhibited in arg-ii−/− mice. Taken together, our study demonstrates a critical role of epithelial Arg-II in activation of pulmonary fibroblasts via paracrine release of IL-1β and TGF-β1, contributing to pulmonary inflammaging and fibrosis. The results provide a novel mechanistic insight in the role of Arg-II in pulmonary aging. 相似文献
Continuous cropping (CC) obstacle is a major threat in legume crops production; however, the underlying mechanisms concerning the roles allelochemicals play in CC obstacle are poorly understood. The current 2-year study was conducted to investigate the effects of different kinds and concentrations of allelochemicals, p-hydroxybenzoic acid (H), cinnamic acid (C), phthalic acid (P), and their mixtures (M) on peanut root growth and productivity in response to CC obstacle. Treatment with H, C, P, and M significantly decreased the plant height, dry weight of the leaves and stems, number of branches, and length of the lateral stem compared with control. Exogenous application of H, C, P, and M inhibited the peanut root growth as indicated by the decreased root morphological characters. The allelochemicals also induced the cell membrane oxidation even though the antioxidant enzymes activities were significantly increased in peanut roots. Meanwhile, treatment with H, C, P, and M reduced the contents of total soluble sugar and total soluble protein. Analysis of ATPase activity, nitrate reductase activity, and root system activity revealed that the inhibition effects of allelochemicals on peanut roots might be due to the decrease in activities of ATPase and NR, and the inhibition of root system. Consequently, allelochemicals significantly decreased the pod yield of peanut compared with control. Our results demonstrate that allelochemicals play a dominant role in CC obstacle-induced peanut growth inhibition and yield reduction through damaging the root antioxidant system, unbalancing the osmolytes accumulation, and decreasing the activities of root-related enzymes.
In the process of bioethanol production, more stable and active cellulase in high temperature condition is required. In this study, syringic acid was applied in cellulase hydrolysis system. At 70°C, TvEG3 activity increased 201.36%, CtBglA activity decreased 72.79% by syringic acid. With syringic acid assisting, TvEG3 thermostability was improved, CtBglA thermostability was reduced. Syringic acid scarcely affected CtCBH. In hydrolysis system with the cellulases containing TvEG3, CtCBH, and CtBglA, the reducing sugar yield improved by 28.37% with syringic acid assisting. With the molecular dynamic simulation in syringic acid system, the backbone root-mean-square deviation (RMSD) and the residue root-mean-square fluctuation (RMSF) of TvEG3, CtCBH reduced, while the RMSD and RMSF of CtBglA increased. The reduction in the number of secondary structures, especially α-helix, caused the structure of CtBglA in the presence of syringic acid to collapse at high temperature. More secondary structures in TvEG3 and more α-helix in CtCBH in the presence of syringic acid make them more stable at high temperatures. These means syringic acid can stabilize TvEG3 and CtCBH structure, destabilize CtBglA structure at high temperature. In summary, this study not only provides insight into cellulase hydrolysis at high temperature with syringic acid assisting but also demonstrates the promoting mechanism of syringic acid. 相似文献