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161.
162.
Susan K. Boehlein Peng Liu Ashley Webster Camila Ribeiro Masaharu Suzuki Shan Wu Jiahn‐Chou Guan Jon D. Stewart William F. Tracy A. Mark Settles Donald R. McCarty Karen E. Koch Larkin C. Hannah Tracie A. Hennen‐Bierwagen Alan M. Myers 《The Plant journal : for cell and molecular biology》2019,99(1):23-40
163.
Guillaume Lentendu Paulo Roberto Bressan Buosi Adalgisa Fernada Cabral Bianca Trevizan Segvia Bianca Ramos Meira Fernando Miranda Lansac‐Tha Luiz Felipe Machado Velho Camila D. Ritter Micah Dunthorn 《The Journal of eukaryotic microbiology》2019,66(4):592-599
The biodiversity and biogeography of protists inhabiting many ecosystems have been intensely studied using different sequencing approaches, but tropical ecosystems are relatively under‐studied. Here, we sampled planktonic waters from 32 lakes associated with four different river–floodplains systems in Brazil, and sequenced the DNA using a metabarcoding approach with general eukaryotic primers. The lakes were dominated by the largely free‐living Discoba (mostly the Euglenida), Ciliophora, and Ochrophyta. There was low community similarity between lakes even within the same river–floodplain. The protists inhabiting these floodplain systems comprise part of the large and relatively undiscovered diversity in the tropics. 相似文献
164.
Adela Martin‐Vicente Ana Camila Oliveira Souza Qusai Al Abdallah Wenbo Ge Jarrod R. Fortwendel 《Cellular microbiology》2019,21(6)
Proper hyphal morphogenesis is essential for the establishment and progression of invasive disease caused by filamentous fungi. In the human pathogen Aspergillus fumigatus, signalling cascades driven by Ras and Ras‐like proteins orchestrate a wide variety of cellular processes required for hyphal growth. For activation, these proteins require interactions with Ras‐subfamily‐specific guanine nucleotide exchange factors (RasGEFs). Although Ras‐protein networks are essential for virulence in all pathogenic fungi, the importance of RasGEF proteins is largely unexplored. A. fumigatus encodes four putative RasGEFs that represent three separate classes of RasGEF proteins (SH3‐, Ras guanyl nucleotide‐releasing protein [RasGRP]–, and LTE‐class), each with fungus‐specific attributes. Here, we show that the SH3‐class and RasGRP‐class RasGEFs are required for properly timed polarity establishment during early growth and branch emergence as well as for cell wall stability. Further, we show that SH3‐class RasGEF activity is essential for polarity establishment and maintenance, a phenotype that is, at least, partially independent of the major A. fumigatus Ras proteins, RasA and RasB. Finally, loss of both SH3‐class RasGEFs resulted in avirulence in multiple models of invasive aspergillosis. Together, our findings suggest that RasGEF activity is essential for the integration of multiple signalling networks to drive invasive growth in A. fumigatus. 相似文献
165.
The body shape of a species is associated with its evolutionary history and can reflect behavioural peculiarities related to the ecological niche of each species. Morphology can characterise the morphometric niche of species and can be represented as body shape points within a morphometric universe. This information can be to calculate the morphometric diversity of communities through hypervolume metrics, and the hole sizes that remain in the morphometric hypervolume, which are empty areas with no species. Such holes may be ‘natural’ or caused by a local extinction. In this study, we evaluate the ecological community of dung beetles through the lens of morphometric diversity. We evaluated 38 dung beetle species from 30 subtropical communities in southern Brazil sampled in the summer of 2015, including 15 forest remnant communities from the Atlantic Forest and 15 communities from adjacent maize cultivations. The shape of 495 dung beetle specimens was measured using geometric morphometric and hypervolume techniques to calculate the morphometric diversity and the hole size of each of the 30 communities. We found that the taxonomic diversity positively correlated with the morphometric diversity and negatively correlated with the size of the holes. We also found that forest communities had higher values of morphometric diversity and smaller holes in the hypervolume than the maize cultivation communities, suggesting that local extinction may reduce community body shape spaces. 相似文献
166.
Paulo Eduardo Menezes‐Silva Lucas Loram‐Loureno Rauander Douglas Ferreira Barros Alves Letícia Ferreira Sousa Sabrina Emanuella da Silva Almeida Fernanda Santos Farnese 《Ecology and evolution》2019,9(20):11979-11999
Anthropogenic activities such as uncontrolled deforestation and increasing greenhouse gas emissions are responsible for triggering a series of environmental imbalances that affect the Earth's complex climate dynamics. As a consequence of these changes, several climate models forecast an intensification of extreme weather events over the upcoming decades, including heat waves and increasingly severe drought and flood episodes. The occurrence of such extreme weather will prompt profound changes in several plant communities, resulting in massive forest dieback events that can trigger a massive loss of biodiversity in several biomes worldwide. Despite the gravity of the situation, our knowledge regarding how extreme weather events can undermine the performance, survival, and distribution of forest species remains very fragmented. Therefore, the present review aimed to provide a broad and integrated perspective of the main biochemical, physiological, and morpho‐anatomical disorders that may compromise the performance and survival of forest species exposed to climate change factors, particularly drought, flooding, and global warming. In addition, we also discuss the controversial effects of high CO2 concentrations in enhancing plant growth and reducing the deleterious effects of some extreme climatic events. We conclude with a discussion about the possible effects that the factors associated with the climate change might have on species distribution and forest composition. 相似文献
167.
Valcilaine T. Barbosa Joyelanne K. C. Souza Valter Alvino Mario R. Meneghetti Pedro P. Florez-Rodriguez Rui E. Moreira Gustavo V. B. Paulino Melissa F. Landell Irinaldo D. Basílio-Júnior Ticiano G. do Nascimento Luciano A. M. Grillo Camila B. Dornelas 《Biotechnology progress》2019,35(6):e2888
Biological methods have been used to synthesize silver nanoparticles through materials such as bacteria, fungi, plants, and propolis due to their reducing properties, stabilizer role and environmentally friendly characteristic. Considering the antimicrobial activity of propolis as well as the broad-spectrum antibacterial effects of silver nanoparticles, this study aim to describe the use of Brazilian propolis to synthesize silver nanoparticles (AgNP-P) and investigate its antimicrobial activity. The synthesis was optimized by factorial design, choosing the best conditions for smaller size particles. AgNP-P demonstrated a maximum absorbance at 412 nm in ultraviolet-visible spectra, which indicated a spherical format and its formation. Dynamic light scattering demonstrated a hydrodynamic size of 109 nm and polydispersity index less than 0.3, showing a good size distribution and stability. After its purification via centrifugation, microscopy analysis corroborates the format and showed the presence of propolis around silver nanoparticle. X-ray diffraction peaks were attributed to the main planes of the metallic silver crystalline structure; meanwhile infrared spectroscopy demonstrated the main groups responsible for silver reduction, represented by ∼22% of AgNP-P indicates by thermal analysis. Our product revealed an important antimicrobial activity indicating a synergism between propolis and silver nanoparticles as expected and promising to be an effective antimicrobial product to be used in infections. 相似文献
168.
169.
Heme induces neutrophil migration and reactive oxygen species generation through signaling pathways characteristic of chemotactic receptors 总被引:3,自引:0,他引:3
Porto BN Alves LS Fernández PL Dutra TP Figueiredo RT Graça-Souza AV Bozza MT 《The Journal of biological chemistry》2007,282(33):24430-24436
Hemolysis or extensive cell damage can lead to high concentrations of free heme, causing oxidative stress and inflammation. Considering that heme induces neutrophil chemotaxis, we hypothesize that heme activates a G protein-coupled receptor. Here we show that similar to heme, several heme analogs were able to induce neutrophil migration in vitro and in vivo. Mesoporphyrins, molecules lacking the vinyl groups in their rings, were not chemotactic for neutrophils and selectively inhibited heme-induced migration. Moreover, migration of neutrophils induced by heme was abolished by pretreatment with pertussis toxin, an inhibitor of Galpha inhibitory protein, and with inhibitors of phosphoinositide 3-kinase, phospholipase Cbeta, mitogen-activated protein kinases, or Rho kinase. The induction of reactive oxygen species by heme was dependent of Galpha inhibitory protein and phosphoinositide 3-kinase and partially dependent of phospholipase Cbeta, protein kinase C, mitogen-activated protein kinases, and Rho kinase. Together, our results indicate that heme activates neutrophils through signaling pathways that are characteristic of chemoattractant molecules and suggest that mesoporphyrins might prove valuable in the treatment of the inflammatory consequences of hemorrhagic and hemolytic disorders. 相似文献
170.