scholarly journals Evidence for Succession and Putative Metabolic Roles of Fungi and Bacteria in the Farming Mutualism of the Ambrosia Beetle Xyleborus affinis

mSystems ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
L. A. Ibarra-Juarez ◽  
M. A. J. Burton ◽  
P. H. W. Biedermann ◽  
L. Cruz ◽  
D. Desgarennes ◽  
...  

Ambrosia beetles farm their own food fungi within tunnel systems in wood and are among the three insect lineages performing agriculture (the others are fungus-farming ants and termites). In ambrosia beetles, primary ambrosia fungus cultivars have been regarded essential, whereas other microbes have been more or less ignored. Our KEGG analyses suggest so far unknown roles of yeasts and bacterial symbionts, by preparing the tunnel walls for the primary ambrosia fungi. This preparation includes enzymatic degradation of wood, essential amino acid production, and nitrogen fixation. The latter is especially exciting because if it turns out to be present in vivo in ambrosia beetles, all farming animals (including humans) are dependent on atmospheric nitrogen fertilization of their crops. As previous internal transcribed spacer (ITS) metabarcoding approaches failed on covering the primary ambrosia fungi, our 18S metabarcoding approach can also serve as a template for future studies on the ambrosia beetle-fungus symbiosis.

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1223
Author(s):  
Jaroslav Holuša ◽  
Tomáš Fiala ◽  
Jiří Foit

Research Highlights: The percentage of canopy closure was found to be the main factor associated with ambrosia beetle abundance and species richness. The latter two variables increased as canopy closure increased, probably because a high percentage of canopy closure provides a stable and humid environment suitable for the growth of ambrosia fungi. Objectives: Oak is a common host tree for ambrosia beetles (Coleoptera: Curculionidae: Scolytinae), which have independently evolved a nutritional mutualism with fungi. We suspected that ambrosia beetles might have specific habitat preferences that are different from those of other saproxylic beetles and that reflect the specific habitat preferences of their food, i.e., ambrosia fungi. Methods: We assessed ambrosia beetle abundance with ethanol-lured traps in five old-growth oak dominated forests and five managed oak dominated forests (one trap per forest) during the vegetation period in 2020. We determined whether ambrosia beetle abundance and species richness depend on forest type (managed vs. unmanaged), degree of canopy closure, abundance of oak trees, abundance of coarse deadwood, and abundance of dead oak branches. Results: In total, 4137 individuals of six species of ambrosia beetles associated with oaks were captured. The native ambrosia beetle Anisandrus dispar represented the majority of trapped ambrosia bark beetles. A. dispar along with another ambrosia beetle, Xyleborinus saxesenii, represented 99% of all captured beetles. Conclusions: In addition to canopy closure, the abundance of oak trees and the abundance of dead oak branches were significantly associated with ambrosia beetle abundance and species richness. The abundance of A. dispar was mainly correlated with dead oak branch abundance and the degree of canopy closure, whereas the abundances of X. saxesenii and of the invasive species Xyleborinus attenuatus and Cyclorhipidion bodoanum were mainly correlated with the net area occupied by oak trees.


2018 ◽  
Vol 115 (17) ◽  
pp. 4447-4452 ◽  
Author(s):  
Christopher M. Ranger ◽  
Peter H. W. Biedermann ◽  
Vipaporn Phuntumart ◽  
Gayathri U. Beligala ◽  
Satyaki Ghosh ◽  
...  

Animal–microbe mutualisms are typically maintained by vertical symbiont transmission or partner choice. A third mechanism, screening of high-quality symbionts, has been predicted in theory, but empirical examples are rare. Here we demonstrate that ambrosia beetles rely on ethanol within host trees for promoting gardens of their fungal symbiont and producing offspring. Ethanol has long been known as the main attractant for many of these fungus-farming beetles as they select host trees in which they excavate tunnels and cultivate fungal gardens. More than 300 attacks by Xylosandrus germanus and other species were triggered by baiting trees with ethanol lures, but none of the foundresses established fungal gardens or produced broods unless tree tissues contained in vivo ethanol resulting from irrigation with ethanol solutions. More X. germanus brood were also produced in a rearing substrate containing ethanol. These benefits are a result of increased food supply via the positive effects of ethanol on food-fungus biomass. Selected Ambrosiella and Raffaelea fungal isolates from ethanol-responsive ambrosia beetles profited directly and indirectly by (i) a higher biomass on medium containing ethanol, (ii) strong alcohol dehydrogenase enzymatic activity, and (iii) a competitive advantage over weedy fungal garden competitors (Aspergillus, Penicillium) that are inhibited by ethanol. As ambrosia fungi both detoxify and produce ethanol, they may maintain the selectivity of their alcohol-rich habitat for their own purpose and that of other ethanol-resistant/producing microbes. This resembles biological screening of beneficial symbionts and a potentially widespread, unstudied benefit of alcohol-producing symbionts (e.g., yeasts) in other microbial symbioses.


Author(s):  
V. Ramadas ◽  
G. Chandralega

Sponges, exclusively are aquatic and mostly marine, are found from the deepest oceans to the edge of the sea. There are approximately 15,000 species of sponges in the world, of which, 150 occur in freshwater, but only about 17 are of commercial value. A total of 486 species of sponges have been identified in India. In the Gulf of Mannar and Palk Bay a maximum of 319 species of sponges have been recorded. It has been proved that marine organisms are excellent source of bioactive secondary metabolites and number of compounds of originated from marine organisms had been reported to possess in-vitro and in-vivo immuno stimulatory activity. Extracts from 20 sponge species were tested for bacterial symbionts and bioactive compounds were isolated from such associated bacterial species in the present study.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2937
Author(s):  
Naima Agouram ◽  
El Mestafa El Hadrami ◽  
Abdeslem Bentama

Natural peptides are an important class of chemical mediators, essential for most vital processes. What limits the potential of the use of peptides as drugs is their low bioavailability and enzymatic degradation in vivo. To overcome this limitation, the development of new molecules mimicking peptides is of great importance for the development of new biologically active molecules. Therefore, replacing the amide bond in a peptide with a heterocyclic bioisostere, such as the 1,2,3-triazole ring, can be considered an effective solution for the synthesis of biologically relevant peptidomimetics. These 1,2,3-triazoles may have an interesting biological activity, because they behave as rigid link units, which can mimic the electronic properties of amide bonds and show bioisosteric effects. Additionally, triazole can be used as a linker moiety to link peptides to other functional groups.


2019 ◽  
Author(s):  
Shivanand Hegde ◽  
Denis Voronin ◽  
Aitor Casas-Sanchez ◽  
Miguel A. Saldaña ◽  
Eva Heinz ◽  
...  

AbstractMicrobiota within mosquitoes influence nutrition, immunity, fecundity, and the capacity to transmit pathogens. Despite their importance, we have a limited understanding of host-microbiota interactions, especially at the cellular level. It is evident bacterial symbionts that are localized within the midgut also infect other organs within the mosquito; however, the route these symbionts take to colonize other tissues is unknown. Here, utilizing the gentamicin protection assay, we showed that the bacterial symbionts Cedecea and Serratia have the capacity to invade and reside intracellularly within mosquito cells. Symbiotic bacteria were found within a vacuole and bacterial replication was observed in mosquito cell by transmission electron microscopy, indicating bacteria were adapted to the intracellular milieu. Using gene silencing, we determined that bacteria exploited host factors, including actin and integrin receptors, to actively invade mosquito cells. As microbiota can affect pathogens within mosquitoes, we examined the influence of intracellular symbionts on Zika virus (ZIKV) infection. Mosquito cells harbouring intracellular bacteria had significantly less ZIKV compared to uninfected cells or cells exposed to non-invasive bacteria. Intracellular bacteria were observed to substantially upregulate the Toll and IMD innate immune pathways, providing a possible mechanism mediating these anti-viral effects. Examining mono-axenically infected mosquitoes using transmission electron and fluorescent microscopy revealed that bacteria occupied an intracellular niche in vivo. Our results provided evidence that bacteria that associate with the midgut of mosquitoes have intracellular lifestyles which likely have implications for mosquito biology and pathogen infection. This study expands our understanding of host-microbiota interactions in mosquitoes, which is important as symbiont microbes are being exploited for vector control strategies.


2018 ◽  
Vol 52 (5) ◽  
pp. 479-489 ◽  
Author(s):  
Sebastian T Müller ◽  
Annekathrin M Keiler ◽  
Kristin Kräker ◽  
Oliver Zierau ◽  
Ricardo Bernhardt

Bone protection and metabolism are directly linked to estrogen levels, but exercise is also considered to have bone protective effects. Reduced estrogen levels lead to a variety of disorders, for example, bone loss and reduced movement drive. The objective of this study was to investigate the effects of estrogen on individual voluntary exercise motivation and bone protection. We investigated sham operated, ovariectomized, and ovariectomized with estrogen supplemented Wistar rats (20 weeks old) either with or without access to exercise wheels. We selected an experimental approach where we could monitor the individual exercise of group-housed rats with ad libitum access to a running wheel with the help of a subcutaneous chip. In vivo and ex vivo microcomputed tomography analyses of the tibia were performed at two-week intervals from week 0 to week 6. Furthermore, tibial trabecular structure was evaluated based on histomorphometric analyses. We observed a significant bone protective effect of E2. For exercise performance, a substantially high intra-group variability was observed, especially in the E2 group. We presume that dominant behavior occurs within the group-housed rats resulting in a hierarchical access to the running wheel and a high variability of distance run. Exercise did not prevent ovariectomy-induced bone loss. However, lack of estrogen within the ovariectomized rats led to a drastically reduced activity prevented by estrogen supplementation. Our findings are important for future studies working with group-housed rats and exercise. The reason for the high intra-group variability in exercise needs to be investigated in future studies.


Nanomedicine ◽  
2021 ◽  
Author(s):  
Milad Ghorbani ◽  
Zhila Izadi ◽  
Samira Jafari ◽  
Eudald Casals ◽  
Foroogh Rezaei ◽  
...  

The wide prevalence of oxidative stress-induced diseases has led to a growing demand for antioxidant therapeutics worldwide. Nanozyme antioxidants are drawing enormous attention as practical alternatives for conventional antioxidants. The considerable body of research over the last decade and the promising results achieved signify the potential of nanozyme antioxidants to secure a place in the expanding market of antioxidant therapeutics. Nonetheless, there is no report on clinical trials for their further evaluation. Through analyzing in-depth selected papers which have conducted in vivo studies on nanozyme antioxidants, this review aims to pinpoint and discuss possible reasons impeding development of research toward clinical studies and to offer some practical solutions for future studies to bridge the gap between preclinical and clinical stages.


2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Pedram Honarpisheh ◽  
Juneyoung Lee ◽  
Anik Banerjee ◽  
Maria P. Blasco-Conesa ◽  
Parisa Honarpisheh ◽  
...  

Abstract Background The ability to distinguish resident microglia from infiltrating myeloid cells by flow cytometry-based surface phenotyping is an important technique for examining age-related neuroinflammation. The most commonly used surface markers for the identification of microglia include CD45 (low-intermediate expression), CD11b, Tmem119, and P2RY12. Methods In this study, we examined changes in expression levels of these putative microglia markers in in vivo animal models of stroke, cerebral amyloid angiopathy (CAA), and aging as well as in an ex vivo LPS-induced inflammation model. Results We demonstrate that Tmem119 and P2RY12 expression is evident within both CD45int and CD45high myeloid populations in models of stroke, CAA, and aging. Interestingly, LPS stimulation of FACS-sorted adult microglia suggested that these brain-resident myeloid cells can upregulate CD45 and downregulate Tmem119 and P2RY12, making them indistinguishable from peripherally derived myeloid populations. Importantly, our findings show that these changes in the molecular signatures of microglia can occur without a contribution from the other brain-resident or peripherally sourced immune cells. Conclusion We recommend future studies approach microglia identification by flow cytometry with caution, particularly in the absence of the use of a combination of markers validated for the specific neuroinflammation model of interest. The subpopulation of resident microglia residing within the “infiltrating myeloid” population, albeit small, may be functionally important in maintaining immune vigilance in the brain thus should not be overlooked in neuroimmunological studies.


Insects ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 8
Author(s):  
Christopher M. Ranger ◽  
Christopher T. Werle ◽  
Peter B. Schultz ◽  
Karla M. Addesso ◽  
Jason B. Oliver ◽  
...  

Ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) are destructive wood-boring insects of horticultural trees. We evaluated long-lasting insecticide netting for protecting stems against ambrosia beetles. Container-grown eastern redbud, Cercis canadensis, trees were flood-stressed to induce ambrosia beetle attacks, and deltamethrin-treated netting was wrapped from the base of the stem vertically to the branch junction. Trees were deployed under field conditions in Ohio, Virginia, Tennessee, and Mississippi with the following treatments: (1) flooded tree; (2) flooded tree with untreated netting; (3) flooded tree with treated ‘standard mesh’ netting of 24 holes/cm2; (4) flooded tree with treated ‘fine mesh’ netting of 28 holes/cm2; and/or (5) non-flooded tree. Treated netting reduced attacks compared to untreated netting and/or unprotected trees in Mississippi in 2017, Ohio and Tennessee in 2018, and Virginia in 2017–2018. Inconsistent effects occurred in Mississippi in 2018. Fewer Anisandrus maiche, Xylosandrus germanus, and Xyleborinus saxesenii were dissected from trees deployed in Ohio protected with treated netting compared to untreated netting; trees deployed in other locations were not dissected. These results indicate long-lasting insecticide netting can provide some protection of trees from ambrosia beetle attacks.


Author(s):  
Nadeen Chahine ◽  
Nate Stetson ◽  
Neena Rajan ◽  
Daniel Grande ◽  
Mitchell Levine

Enzymatic degradation of the intervertebral disc (IVD) with chondroitinase ABC (ChABC) reduces proteoglycan content of the IVD, thus simulating the GAG loss seen clinically in patients suffering from disc degeneration. This approach has been employed in models of disc injury in rats, rabbits and goats when administered over a large range of dosages [1–3]. Moreover, ChABC has also been used to induce repair of herniated discs in rabbits via chemonucleolysis [4, 5]. Despite the effectiveness of ChABC treatment to reduce the GAG content of the IVD, several recent studies including our own, have shown that this GAG loss is reversible at extended time points post enzymatic treatment [2,6,7]. The goal of the current study is to examine the dose dependent response of IVDs to degradation by ChABC in vivo. We hypothesize that administration of ChABC will result in dose dependent GAG loss and reduced mechanical properties. We administered ChABC at 0.1 U/ml, 1.0 U/ml and 10 U/ml and examined the changes in biomechanical properties, biochemical content, and gene expression in order to examine the biophysical and molecular mechanism by which GAG loss occurs in this model.


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