scholarly journals Preliminary Characterization of Phage-like Particles from the Male-Killing Mollicute Spiroplasma poulsonii (an Endosymbiont of Drosophila)

2021 ◽  
Author(s):  
Paulino Ramirez ◽  
Justin C. Leavitt ◽  
Jason J. Gill ◽  
Mariana Mateos

Viruses are vastly abundant and influential in all ecosystems, and are generally regarded as pathogens. Viruses of prokaryotes (themselves highly diverse and abundant) are known as bacteriophages or phages. Phages engage in diverse associations with their hosts, and contribute to regulation of biogeochemical processes, horizontal movement of genes, and control of bacterial populations. Recent studies have revealed the influential role of phage in the association of arthropods and their heritable endosymbiotic bacteria (e.g. the Proteobacteria genera Wolbachia and Hamiltonella). Despite prior studies (~30 years ago) documenting presence of phage in the mollicute Spiroplasma infecting Drosophila, genomic sequences of such phage are lacking, and their effects on the Spiroplasma-Drosophila interaction have not been comprehensively characterized. The present work isolated phage-like particles from the male-killing Spiroplasma poulsonii (strains NSRO and MSRO-Br) harbored by Drosophila melanogaster. Isolated particles were subjected to DNA sequencing, assembly, and annotation. Our results recovered three ~19 kb phage-like contigs (two in NSRO and one in MSRO-Br), and two smaller non-phage-like contigs encoding a known Spiroplasma toxin and an insertion element. Whole or parts of the particle-derived contigs were found in the genome assemblies of members of the Spiroplasma poulsonii clade. Although our results do not allow us to distinguish whether the contigs obtained represent infective phage-like particles capable of transmitting their DNA to new hosts, their encoding of several typical phage genes suggests that they are at least remnants of functional phage. We discuss potential implications of our findings and suggest future directions.

Author(s):  
Maureen L. Whittal ◽  
Melisa Robichaud

The cornerstone of cognitive treatment (CT) for OCD is based upon the knowledge that unwanted intrusions are essentially a universal experience. As such, it is not the presence of the intrusion that is problematic but rather the associated meaning or interpretation. Treatment is flexible, depending upon the nature of the appraisals and beliefs, but can include strategies focused on inflated responsibility and overestimation of threat, importance and control of thoughts, and the need for perfectionism and certainty. The role of concealment and the relationship to personal values are important maintaining and etiological factors. The short-term and long-term treatment outcome is reviewed, along with predictors of treatment response and mechanisms of action, and the chapter concludes with future directions regarding CT for OCD.


2003 ◽  
Vol 52 (4) ◽  
pp. 365-369 ◽  
Author(s):  
K.E. Hill ◽  
C.E. Davies ◽  
M.J. Wilson ◽  
P. Stephens ◽  
K.G. Harding ◽  
...  

There is growing evidence to suggest that the resident microflora of chronic venous leg ulcers impairs cellular wound-healing responses, thereby playing an important role in maintaining the non-healing phenotype of many of these wounds. The significance of individual species of bacteria will remain unclear until it is possible to characterize fully the microflora of such lesions. The limitations and biases of culture-based microbiology are being realized and the subsequent application of molecular methods is revealing greater diversity within mixed bacterial populations than that demonstrated by culture alone. To date, this approach has been limited to a small number of systems, including the oral microflora. Here, for the first time, the comprehensive characterization of the microflora present in the tissue of a chronic venous leg ulcer is described by the comparison of 16S rDNA sequences amplified directly from the wound tissue with sequences obtained from bacteria that were isolated by culture. The molecular approach demonstrated significantly greater bacterial diversity than that revealed by culture. Furthermore, sequences were retrieved that may possibly represent novel species of bacteria. It is only by the comprehensive analysis of the wound microflora by both molecular and cultural methods that it will be possible to further our understanding of the role of bacteria in this important condition.


2020 ◽  
Vol 319 (2) ◽  
pp. F284-F291 ◽  
Author(s):  
Di Feng

Podocyte dysfunction contributes to proteinuric chronic kidney disease. A number of key proteins are essential for podocyte function, including nephrin, podocin, CD2-associated protein (CD2AP), synaptopodin, and α-actinin-4 (ACTN4). Although most of these proteins were first identified through genetic studies associated with human kidney disease, subsequent studies have identified phosphorylation of these proteins as an important posttranslational event that regulates their function. In this review, a brief overview of the function of these key podocyte proteins is provided. Second, the role of phosphorylation in regulating the function of these proteins is described. Third, the association between these phosphorylation pathways and kidney disease is reviewed. Finally, challenges and future directions in studying phosphorylation are discussed. Better characterization of these phosphorylation pathways and others yet to be discovered holds promise for translating this knowledge into new therapies for patients with proteinuric chronic kidney disease.


2015 ◽  
Vol 43 (3) ◽  
pp. 489-494 ◽  
Author(s):  
Sakthivel Vaiyapuri ◽  
Gagan D. Flora ◽  
Jonathan M. Gibbins

Platelets are involved in the maintenance of haemostasis but their inappropriate activation leads to thrombosis, a principal trigger for heart attack and ischaemic stroke. Although platelets circulate in isolation, upon activation they accumulate or aggregate together to form a thrombus, where they function in a co-ordinated manner to prevent loss of blood and control wound repair. Previous report (1) indicates that the stability and functions of a thrombus are maintained through sustained, contact-dependent signalling between platelets. Given the role of gap junctions in the co-ordination of tissue responses, it was hypothesized that gap junctions may be present within a thrombus and mediate intercellular communication between platelets. Therefore studies were performed to explore the presence and functions of connexins in platelets. In this brief review, the roles of hemichannels and gap junctions in the control of thrombosis and haemostasis and the future directions for this research will be discussed.


2004 ◽  
Vol 10 (3) ◽  
pp. 324-335 ◽  
Author(s):  
S.P. Ringer ◽  
K.R. Ratinac

This work reviews recent research on the design and control of interfaces in engineering nanomaterials. Four case studies are presented that demonstrate the power of a multimodal approach to the characterization of different types of interfaces. We have used a combination of conventional, high resolution, and analytical transmission electron microscopy, microbeam electron diffraction, and three-dimensional atom probe to study polymer–clay nanocomposites, turbine rotor steels used for power generation, multicomponent aluminum alloys, and nanocrystalline magnetic materials.


Author(s):  
Ana M. Bedoya ◽  
Adam D. Leaché

AbstractSpiny lizards in the genus Sceloporus are a model system among squamate reptiles for studies of chromosomal evolution. While most pleurodont iguanians retain an ancestral karyotype formula of 2n=36 chromosomes, Sceloporus exhibits substantial karyotype variation ranging from 2n=22 to 2n=46 chromosomes. In this study, we present two annotated chromosome-scale genome assemblies for the Plateau Fence Lizard (Sceloporus tristichus) in order to facilitate research on the role of pericentric inversion polymorphisms on adaptation and speciation. Based on previous karyotype work using conventional staining, the S. tristichus genome is characterized as 2n=22 with 6 pairs of macrochromosomes and 5 pairs of microchromosomes with a large pericentric inversion polymorphism on chromosome seven that is geographically variable. We provide annotated, chromosome-scale genomes for two lizards located at opposite ends of a dynamic hybrid zone that are each fixed for different inversion polymorphisms. The assembled genomes are 1.84 to 1.87 Gb (1.72 Gb for scaffolds mapping to chromosomes) with a scaffold N50 of 267.5 Mb. Functional annotation of the genomes resulted in 65,417 annotated genes, 16,426 of which were deduced to have a function. We confirmed the presence of a 4.62 Mb pericentric inversion on chromosome seven, which contains 59 annotated coding genes with known functions. These new genomic resources provide opportunities to perform genomic scans and investigate the formation and spread of pericentric inversions in a naturally occurring hybrid zone.


2008 ◽  
Vol 411 (2) ◽  
pp. e9-e10 ◽  
Author(s):  
David M. Thomson ◽  
Marc D. H. Hansen ◽  
William W. Winder

How can a constitutively active ‘master’ kinase with numerous downstream targets preferentially phosphorylate one or more of these without influencing all simultaneously? How might such a system be switched off? The characterization of the role of deubiquitination in regulating the phosphorylation and activation of AMPK (AMP-activated protein kinase)-related kinases by LKB1 suggests a novel and interesting mechanism for conferring signal transduction specificity and control at the kinase substrate level. In this issue of the Biochemical Journal, Al-Hakim et al. show that the AMPK-related kinases NUAK1 (AMPK-related kinase 5) and MARK4 (microtubule-affinity-regulating kinase 4) are polyubiquitinated in vivo and that they serve as substrates of the deubiquitinating enzyme USP9X; furthermore, the first evidence is provided for regulation of AMPK-related kinase family members mediated via unusual Lys29/Lys33 polyubiquitin chains, rather than the more common Lys48/Lys63 linkages.


2013 ◽  
Vol 305 (1) ◽  
pp. C1-C21 ◽  
Author(s):  
Noah Alberts-Grill ◽  
Timothy L. Denning ◽  
Amir Rezvan ◽  
Hanjoong Jo

A complex role has been described for dendritic cells (DCs) in the potentiation and control of vascular inflammation and atherosclerosis. Resident vascular DCs are found in the intima of atherosclerosis-prone vascular regions exposed to disturbed blood flow patterns. Several phenotypically and functionally distinct vascular DC subsets have been described. The functional heterogeneity of these cells and their contributions to vascular homeostasis, inflammation, and atherosclerosis are only recently beginning to emerge. Here, we review the available literature, characterizing the origin and function of known vascular DC subsets and their important role contributing to the balance of immune activation and immune tolerance governing vascular homeostasis under healthy conditions. We then discuss how homeostatic DC functions are disrupted during atherogenesis, leading to atherosclerosis. The effectiveness of DC-based “atherosclerosis vaccine” therapies in the treatment of atherosclerosis is also reviewed. We further provide suggestions for distinguishing DCs from macrophages and discuss important future directions for the field.


Author(s):  
Despoina Eugenia Kiousi ◽  
Marina Rathosi ◽  
Margaritis Tsifintaris ◽  
Pelagia Chondrou ◽  
Alex Galanis

ABSTRACT The comprehensive characterization of probiotic action has flourished during the past few decades, alongside the evolution of high-throughput, multiomics platforms. The integration of these platforms into probiotic animal and human studies has provided valuable insights into the holistic effects of probiotic supplementation on intestinal and extraintestinal diseases. Indeed, these methodologies have informed about global molecular changes induced in the host and residing commensals at multiple levels, providing a bulk of metagenomic, transcriptomic, proteomic, and metabolomic data. The meaningful interpretation of generated data remains a challenge; however, the maturation of the field of systems biology and artificial intelligence has supported analysis of results. In this review article, we present current literature on the use of multiomics approaches in probiotic studies, we discuss current trends in probiotic research, and examine the possibility of tailor-made probiotic supplementation. Lastly, we delve deeper into newer technologies that have been developed in the last few years, such as single-cell multiomics analyses, and provide future directions for the maximization of probiotic efficacy.


2021 ◽  
Author(s):  
Zahra Vahedi

Previous research has shown that female viewers generally experience detrimental effects following exposure to idealized media images. However, in experimental studies, demand characteristics – or cues that help the participant deduce the true purpose of the study – might influence the responses participants provide, particularly in studies involving idealized images. The present study investigated the potential role of demand characteristics following exposure to media images. Undergraduate female students (N = 172) were assigned to three groups (Implied Demand, Minimized Demand and Control), two of which were exposed to idealized media images in fashion magazines. Demand characteristics were manipulated when the experimenter provided the magazines during a break period, and participants’ mood was assessed both pre and post-exposure. Contrary to previous research, our results indicated that exposure to magazine images did not have consistently detrimental effects on the measures of participants’ mood. Potential explanations for these results and future directions of research are discussed.


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