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121.
Zhihua Liu John S. Kimball Nicholas C. Parazoo Ashley P. Ballantyne Wen J. Wang Nima Madani Caleb G. Pan Jennifer D. Watts Rolf H. Reichle Oliver Sonnentag Philip Marsh Miriam Hurkuck Manuel Helbig William L. Quinton Donatella Zona Masahito Ueyama Hideki Kobayashi Eugnie S. Euskirchen 《Global Change Biology》2020,26(2):682-696
Arctic and boreal ecosystems play an important role in the global carbon (C) budget, and whether they act as a future net C sink or source depends on climate and environmental change. Here, we used complementary in situ measurements, model simulations, and satellite observations to investigate the net carbon dioxide (CO2) seasonal cycle and its climatic and environmental controls across Alaska and northwestern Canada during the anomalously warm winter to spring conditions of 2015 and 2016 (relative to 2010–2014). In the warm spring, we found that photosynthesis was enhanced more than respiration, leading to greater CO2 uptake. However, photosynthetic enhancement from spring warming was partially offset by greater ecosystem respiration during the preceding anomalously warm winter, resulting in nearly neutral effects on the annual net CO2 balance. Eddy covariance CO2 flux measurements showed that air temperature has a primary influence on net CO2 exchange in winter and spring, while soil moisture has a primary control on net CO2 exchange in the fall. The net CO2 exchange was generally more moisture limited in the boreal region than in the Arctic tundra. Our analysis indicates complex seasonal interactions of underlying C cycle processes in response to changing climate and hydrology that may not manifest in changes in net annual CO2 exchange. Therefore, a better understanding of the seasonal response of C cycle processes may provide important insights for predicting future carbon–climate feedbacks and their consequences on atmospheric CO2 dynamics in the northern high latitudes. 相似文献
122.
Mariane P. Zubieta Jaqueline A. Gerhardt Marcelo V. Rubio César R. F. Terrasan Gabriela F. Persinoti Everton P. Antoniel Fabiano J. Contesini Rolf A. Prade André Damasio 《Microbial biotechnology》2020,13(4):1245-1253
Filamentous fungi are important cell factories for large-scale enzyme production. However, production levels are often low, and this limitation has stimulated research focusing on the manipulation of genes with predicted function in the protein secretory pathway. This pathway is the major route for the delivery of proteins to the cell exterior, and a positive relationship between the production of recombinant enzymes and the unfolded protein response (UPR) pathway has been observed. In this study, Aspergillus nidulans was exposed to UPR-inducing chemicals and differentially expressed genes were identified by RNA-seq. Twelve target genes were deleted in A. nidulans recombinant strains producing homologous and heterologous GH10 xylanases. The knockout of pbnA (glycosyltransferase), ydjA (Hsp40 co-chaperone), trxA (thioredoxin) and cypA (cyclophilin) improved the production of the homologous xylanase by 78, 171, 105 and 125% respectively. Interestingly, these deletions decreased the overall protein secretion, suggesting that the production of the homologous xylanase was specifically altered. However, the production of the heterologous xylanase and the secretion of total proteins were not altered by deleting the same genes. Considering the results, this approach demonstrated the possibility of rationally increase the production of a homologous enzyme, indicating that trxA, cypA, ydjA and pbnA are involved in protein production by A. nidulans. 相似文献
123.
Zhang Hongling Ran Chao Teame Tsegay Ding Qianwen Hoseinifar Seyed Hossein Xie Mingxu Zhang Zhen Yang Yalin Olsen Rolf Erik Gatlin Delbert M. Ringø Einar Duan Ming Zhou Zhigang 《Reviews in Fish Biology and Fisheries》2020,30(4):569-586
Reviews in Fish Biology and Fisheries - The intestinal mucosal barrier plays a critical role in the maintenance of host health. In farmed teleost fish, the intestinal epithelium is challenged by a... 相似文献
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I. Keller J. M. Alexander R. Holderegger P. J. Edwards 《Journal of evolutionary biology》2013,26(12):2527-2543
Altitudinal gradients offer valuable study systems to investigate how adaptive genetic diversity is distributed within and between natural populations and which factors promote or prevent adaptive differentiation. The environmental clines along altitudinal gradients tend to be steep relative to the dispersal distance of many organisms, providing an opportunity to study the joint effects of divergent natural selection and gene flow. Temperature is one variable showing consistent altitudinal changes, and altitudinal gradients can therefore provide spatial surrogates for some of the changes anticipated under climate change. Here, we investigate the extent and patterns of adaptive divergence in animal populations along altitudinal gradients by surveying the literature for (i) studies on phenotypic variation assessed under common garden or reciprocal transplant designs and (ii) studies looking for signatures of divergent selection at the molecular level. Phenotypic data show that significant between‐population differences are common and taxonomically widespread, involving traits such as mass, wing size, tolerance to thermal extremes and melanization. Several lines of evidence suggest that some of the observed differences are adaptively relevant, but rigorous tests of local adaptation or the link between specific phenotypes and fitness are sorely lacking. Evidence for a role of altitudinal adaptation also exists for a number of candidate genes, most prominently haemoglobin, and for anonymous molecular markers. Novel genomic approaches may provide valuable tools for studying adaptive diversity, also in species that are not amenable to experimentation. 相似文献
127.
Marrit Putker Tobias Madl Harmjan R. Vos Hesther de Ruiter Marieke Visscher Maaike C.W. van den Berg Mohammed Kaplan Hendrik C. Korswagen Rolf Boelens Michiel Vermeulen Boudewijn M.T. Burgering Tobias B. Dansen 《Molecular cell》2013,49(4):730-742
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128.
The striated muscles of Derocheilocaris typica consist of mononucleated cells, each containing one filament bundle. Large muscles consist of two or more cells adjacent to each other. The mitochondria line up along the filament bundle on one side. The nucleus is situated in the mitochondrial row and has a small cytoplasmic area around it filled with glycogen. The sarcomeres are between 3 and 6 μm long. The Z-line and H band are present. Six thin filaments surround one thick filament. All muscles belong to the phasic type. The tubular system emanates from the ends of the muscle cell and penetrates the whole cell. The tubules are formed as cisterns, which also open at the cell membrane at the level of the I bands. They have sarcoplasmic cisterns on both sides forming a continuous triad system. Partially transformed epidermal cells mediate muscle insertions on the cuticle. Tendons are formed with the transformed epidermal cells being supplemented by fibroblasts forming collagen fibers. Dorsal and ventral abdominal muscles are innervated from the dorso-lateral nerve arising from the nerve chain. Each muscle cell receives one axon, which forms one synapse on the mitochondrial-free side of the muscles. Axons form terminal spines, which make axo-axonal synapses. 相似文献
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Rico Spangenberg Benjamin Wipfler Katrin Friedemann Hans Pohl Christiane Weirauch Viktor Hartung Rolf G. Beutel 《Arthropod Structure & Development》2013,42(4):315-337
External and internal head structures of Coleorrhyncha, a key-taxon within the Hemiptera, are described in detail and documented using modern techniques. The main focus is on Hackeriella veitchi, but two additional representatives of the Gondwanan relict group were also examined, and also head structures of Enicocephalidae, a member of a potentially basal heteropteran lineage. Features were compared to those documented in literature for the Sternorrhyncha, Auchenorrhyncha, and Heteroptera. Coleorrhyncha are characterized by highly modified head structures and correspondingly an entire series of autapomorphies, such as for instance a strongly flattened head capsule with fenestrations. However, they also display features that are likely plesiomorphic compared to members of other hemipteran groups. These include the almost complete tentorium and the lack of the gula. The sistergroup relationship between Coleorrhyncha and Heteroptera is well supported by cephalic features. Potential synapomorphies are the presence of a distinct mandibular sulcus, the reduced number of antennomeres, the absence of clasping organs in the labial groove, coiled accessory salivary ducts, the presence of a small cervical muscle M1a (M. pronotopostoccipitalis medialis), the presence of a second mandibular promotor M14 (M. zygomaticus mandibulae), the presence of M28 (M. verticopharyngalis), and M30 (M. frontobuccalis posterior). 相似文献