Comparative Insight into the Bacterial Communities in Alate and Apterous Morphs of Brown Citrus Aphid (Hemiptera: Aphididae)

2020 ◽  
Vol 113 (3) ◽  
pp. 1436-1444
Author(s):  
Feng Shang ◽  
Jinzhi Niu ◽  
Bi-Yue Ding ◽  
Jin-Jun Wang

Abstract Wing polyphenism (alate and apterous morphs) in aphids is a trade-off between dispersal and reproduction. How bacterial communities are associated with wing polyphenism in aphids is still not clearly understood. This study used 16S rRNA sequencing to examine the differences in diversity of the bacterial community between alate and apterous morphs in Aphis citricidus, the main vector of the Citrus tristeza virus. Eighty-one operational taxonomic units (OTUs) belonging to 37 orders, 34 classes, and 13 phyla were identified from all samples. Among these OTUs, Wolbachia (79.17%), Buchnera (17.64%), and Pseudomonas (2.99%) were the dominant bacterial genera. The diversity of symbionts varied between the two morphs; apterous morphs had more bacterial diversity (69 OTUs belonging to 45 families, 21 classes, and 12 phyla) than alate morphs (45 OTUs belonging to 36 families, 15 classes, and 10 phyla). In addition, the abundance of five OTUs was significantly different between two morphs. Among these OTUs, two Pseudomonas species (Pseudomonas_brenneri [OTU21] and unclassified_Pseudomonas [OTU13]) represented a high proportion (3.93% and 2.06%) in alate morphs but were present in low abundance (0.006% and 0.002%) in apterous morphs. RT-qPCR showed consistent results with high-throughput DNA sequencing. The preliminary survey showed the difference in composition and frequency of bacteria between alate and apterous morphs. Thus, the results contribute to anew insight of microorganisms that may be involved in wing dimorphism and helpful for controlling the dispersal of this pest through artificial elimination or reinfection of bacterial symbionts or targeting symbiosis-related host genes by RNA interference in future.

2018 ◽  
Vol 59 (77) ◽  
pp. 10-20 ◽  
Author(s):  
Roberto Sergio Azzoni ◽  
Ilario Tagliaferri ◽  
Andrea Franzetti ◽  
Christoph Mayer ◽  
Astrid Lambrecht ◽  
...  

ABSTRACTSnow can be considered an independent ecosystem that hosts active microbial communities. Snow microbial communities have been extensively investigated in the Arctic and in the Antarctica, but rarely in mid-latitude mountain areas. In this study, we investigated the bacterial communities of snow collected in four glacierized areas (Alps, Eastern Anatolia, Karakoram and Himalaya) by high-throughput DNA sequencing. We also investigated the origin of the air masses that produced the sampled snowfalls by reconstructing back-trajectories. A standardized approach was applied to all the analyses in order to ease comparison among different communities and geographical areas. The bacterial communities hosted from 25 to 211 Operational Taxonomic Units (OTUs), and their structure differed significantly between geographical areas. This suggests that snow bacterial communities may largely derive from ‘local’ air bacteria, maybe by deposition of airborne particulate of local origin that occurs during snowfall. However, some evidences suggest that a contribution of bacteria collected during air mass uplift to snow communities cannot be excluded, particularly when the air mass that originated the snow event is particularly rich in dust.


2019 ◽  
Vol 41 (4) ◽  
pp. 561-565 ◽  
Author(s):  
Birthe Zäncker ◽  
Anja Engel ◽  
Michael Cunliffe

Abstract Transparent exopolymer particles (TEP) are polysaccharide-rich microgels that are prevalent in the marine environment and have important roles in the aggregation of organic matter and carbon export from the euphotic zone. TEP are readily colonized by bacteria and utilized by specialized taxa, such as Alteromonadaceae. However, bacterial community composition specifically attached to natural TEP remains largely unknown. In this study, we isolated individual TEP from Plymouth Sound (UK) and performed DNA sequencing of the TEP-attached bacterial communities. We also sampled the cognate bulk seawater total bacterial communities for comparison. The bacterial communities associated with individual TEP showed distinct differences compared to the total bulk bacterioplankton communities, with Alteromonadaceae significantly more abundant on TEP. The TEP-associated Alteromonadaceae consisted of two operational taxonomic units that were closely related to Marinobacter and Glaciecola, both previously associated with biogenic aggregates and microgel-rich habitats. This study provides novel insight into marine bacterial–microgel interactions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shukria Akbar ◽  
D. Cole Stevens

AbstractPredation contributes to the structure and diversity of microbial communities. Predatory myxobacteria are ubiquitous to a variety of microbial habitats and capably consume a broad diversity of microbial prey. Predator–prey experiments utilizing myxobacteria have provided details into predatory mechanisms and features that facilitate consumption of prey. However, prey resistance to myxobacterial predation remains underexplored, and prey resistances have been observed exclusively from predator–prey experiments that included the model myxobacterium Myxococcus xanthus. Utilizing a predator–prey pairing that instead included the myxobacterium, Cystobacter ferrugineus, with Pseudomonas putida as prey, we observed surviving phenotypes capable of eluding predation. Comparative transcriptomics between P. putida unexposed to C. ferrugineus and the survivor phenotype suggested that increased expression of efflux pumps, genes associated with mucoid conversion, and various membrane features contribute to predator avoidance. Unique features observed from the survivor phenotype when compared to the parent P. putida include small colony variation, efflux-mediated antibiotic resistance, phenazine-1-carboxylic acid production, and increased mucoid conversion. These results demonstrate the utility of myxobacterial predator–prey models and provide insight into prey resistances in response to predatory stress that might contribute to the phenotypic diversity and structure of bacterial communities.


2021 ◽  
Vol 9 (3) ◽  
pp. 659
Author(s):  
Elias Asimakis ◽  
Panagiota Stathopoulou ◽  
Apostolis Sapounas ◽  
Kanjana Khaeso ◽  
Costas Batargias ◽  
...  

Various factors, including the insect host, diet, and surrounding ecosystem can shape the structure of the bacterial communities of insects. We have employed next generation, high-throughput sequencing of the 16S rRNA to characterize the bacteriome of wild Zeugodacus (Bactrocera) cucurbitae (Coquillett) flies from three regions of Bangladesh. The tested populations developed distinct bacterial communities with differences in bacterial composition, suggesting that geography has an impact on the fly bacteriome. The dominant bacteria belonged to the families Enterobacteriaceae, Dysgomonadaceae and Orbaceae, with the genera Dysgonomonas, Orbus and Citrobacter showing the highest relative abundance across populations. Network analysis indicated variable interactions between operational taxonomic units (OTUs), with cases of mutual exclusion and copresence. Certain bacterial genera with high relative abundance were also characterized by a high degree of interactions. Interestingly, genera with a low relative abundance like Shimwellia, Gilliamella, and Chishuiella were among those that showed abundant interactions, suggesting that they are also important components of the bacterial community. Such knowledge could help us identify ideal wild populations for domestication in the context of the sterile insect technique or similar biotechnological methods. Further characterization of this bacterial diversity with transcriptomic and metabolic approaches, could also reveal their specific role in Z. cucurbitae physiology.


PEDIATRICS ◽  
1956 ◽  
Vol 18 (6) ◽  
pp. 959-978
Author(s):  
Hugh W. Josephs

In this work the author has attempted to gain insight into the significance of iron depletion by the use of 4 simple calculations, justification for which is found in recent articles. These are: (a) iron with which the infant is born; (b) iron retained from the food; (c) iron being used by the tissues and therefore unavailable for hemoglobin, and (d) iron combined with the total mass of hemoglobin. With these 4 figures it is possible to estimate the iron still potentially available for use (the "reserves" or "stones"). When the difference between a + b and c + d has reached about zero, depletion is considered to exist. The following characteristics of depletion may be emphasized: Depletion is the result of gain in weight and maximum possible usage of iron. It is therefore a normal result of growth and need not be associated with anemia. As soon as depletion has occurred, the organism is thereafter dependent on current absorption of iron. This is ordinarily sufficient, even with a diet of milk alone, to maintain an adequate concentration of hemoglobin after about 8 to 10 months of age. Severe anemia due to depletion alone is practically confined to premature babies whose relative gain in weight is rapid. Severe anemia in other than premature babies is the result of a number of factors by which iron becomes unavailable or is actually diverted from hemoglobin to storage. Response to iron medication is considerably better in infants with depletion than in those in whom some factor is present that interferes with iron utilization, and which is not connected by the mere giving of iron. The dependence on current absorption, whether the result of depletion or non-availability, introduces a certain precariousness which is apparently characteristic of this time of life. The organism gets along from day to day if nothing happens, but may not be able to meet an emergency, whether this appears as a rapid gain in weight, or a necessity to repair damage done by severe infection. If we consider iron deficiency as the cause of anemia, we can think of deficiency as due to a number of factors of which depletion is only one. The development and characteristics of depletion have been considered in this paper; other factors in iron deficiency will be considered in subsequent papers.


2017 ◽  
Vol 28 (3) ◽  
pp. 315-317 ◽  
Author(s):  
Josef Wagner ◽  
Sarah Kerry-Barnard ◽  
ST Sadiq ◽  
Pippa Oakeshott

2018 ◽  
Vol 9 ◽  
Author(s):  
Rui P. A. Pereira ◽  
Jörg Peplies ◽  
Douglas Mushi ◽  
Ingrid Brettar ◽  
Manfred G. Höfle

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Qin Lian ◽  
Chunxu Yang ◽  
Jifei Cao

The transition between static and kinetic frictions of steel/shale pairs has been studied. It was found that the coefficient of friction decreased exponentially from static to dynamic friction coefficient with increasing sliding displacement. The difference between static and dynamic friction coefficients and the critical distance Dc under the dry friction condition is much larger than that under the lubricated condition. The transition from static to dynamic friction coefficient is greatly affected by the normal load, quiescent time, and sliding velocity, especially the lubricating condition. Maintaining continuous lubrication of the contact area by the lubricant is crucial to reduce or eliminate the stick-slip motion. The results provide an insight into the transition from static to dynamic friction of steel/shale pairs.


2004 ◽  
Vol 3 (1) ◽  
pp. 19-29
Author(s):  
Tomy Kallarackal

The Value Added Tax was first introduced in France in 1954. It was the resultant effort of France and members of the European Economic Community (E.E.C) during the 1950s aimed at the simplification of commodity taxes. Currently more than 130 nations in the world have adopted the VAT system. In the last decade alone over 50 nations have introduced VAT. This includes implementation in China and most recently the addition of Australia to the list of VAT nations. The world over, VAT is payable on both goods and services as they constitute a part of the national GDR Excise duty and sales taxes are merged into the singularity of VAT. No tax is levied on exports with full input tax credit made available. The scheme of taxation adopted by most nations is very simple. The seller of goods and the service provider charge tax on sales, avail input tax credit and pay the difference as VAT to the goVernment treasury. The compliance system in VAT nations is also very simple. There is very less interface between the tax collector and the tax payer. However there are provisions for heavy penalization of VAT defaulters. VAT is administered nationally and is also levied on imports.  


2021 ◽  
Vol 111 (1) ◽  
pp. 8-11
Author(s):  
Remco Stam ◽  
Pierre Gladieux ◽  
Boris A. Vinatzer ◽  
Erica M. Goss ◽  
Neha Potnis ◽  
...  

Population genetics has been a key discipline in phytopathology for many years. The recent rise in cost-effective, high-throughput DNA sequencing technologies, allows sequencing of dozens, if not hundreds of specimens, turning population genetics into population genomics and opening up new, exciting opportunities as described in this Focus Issue . Without the limitations of genetic markers and the availability of whole or near whole-genome data, population genomics can give new insights into the biology, evolution and adaptation, and dissemination patterns of plant-associated microbes.


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