scholarly journals Interactions between Coexisting Intracellular Genomes: Mitochondrial Density and Wolbachia Infection

2009 ◽  
Vol 75 (7) ◽  
pp. 1916-1921 ◽  
Author(s):  
L. Mouton ◽  
H. Henri ◽  
F. Fleury
Keyword(s):  
Mitochondrial Dna ◽  
Selective Sweep ◽  
Wolbachia Infection ◽  
Host Cells ◽  
Unanswered Question ◽  
Mitochondrial Density ◽  
Leptopilina Heterotoma ◽  
Asobara Tabida ◽  
Evolutionary Aspects

ABSTRACT Many arthropods are infected with maternally transmitted microorganisms, leading to the coexistence of several intracellular genomes within the host cells, including their own mitochondria. As these genomes are cotransmitted, their patterns of evolution have been intimately linked, with possible consequences for the diversity and evolution of the host mitochondrial DNA. The evolutionary aspects of the situation have been thoroughly investigated, especially the selective sweep on the mitochondria as a result of Wolbachia invasion, whereas direct interactions between mitochondria and intracellular symbionts within the host cells or body have received little attention. Since endosymbionts exploit host resources but mitochondria supply energy to meet the bioenergetic demands of organisms, an unanswered question concerns the correlation between their densities. Here, we investigated the influence of Wolbachia symbiosis on mitochondrial density in two parasitic wasps of Drosophila species, both of which are naturally infected by three Wolbachia strains, but they differ in their degree of dependency on these bacteria. In Leptopilina heterotoma, all Wolbachia strains are facultative, whereas Asobara tabida requires a strain of Wolbachia for oogenesis to occur. In both species, Wolbachia infections are stable and well regulated, since the density of each strain does not depend on the presence or absence of other strains. Using lines that harbor various Wolbachia infection statuses, we found that mitochondrial density was not affected by the infection regardless of the sex and age of the host, which is strongly reminiscent of the independent regulation of specific Wolbachia strains and suggest that the protagonists coexist independently of each other as the result of a long-term coevolutionary interaction.

scholarly journals Genetic Consequences of Fence Confinement in a Population of White-Tailed Deer

Diversity ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 126
Author(s):  
Emily K. Latch ◽  
Kenneth L. Gee ◽  
Stephen L. Webb ◽  
Rodney L. Honeycutt ◽  
Randy W. DeYoung ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mitochondrial Dna ◽  
Wildlife Management ◽  
Field Observations ◽  
Adaptive Potential ◽  
Population Isolation ◽  
Potential Benefits ◽  
Wildlife Populations ◽  
Mtdna Diversity

Fencing wildlife populations can aid wildlife management goals, but potential benefits may not always outweigh costs of confinement. Population isolation can erode genetic diversity and lead to the accumulation of inbreeding, reducing viability and limiting adaptive potential. We used microsatellite and mitochondrial DNA data collected from 640 white-tailed deer confined within a 1184 ha fence to quantify changes in genetic diversity and inbreeding over the first 12 years of confinement. Genetic diversity was sustained over the course of the study, remaining comparable to unconfined white-tailed deer populations. Uneroded genetic diversity suggests that genetic drift is mitigated by a low level of gene flow, which supports field observations that the fence is not completely impermeable. In year 9 of the study, we observed an unexpected influx of mtDNA diversity and drop in inbreeding as measured by FIS. A male harvest restriction imposed that year increased male survival, and more diverse mating may have contributed to the inbreeding reduction and temporary genetic diversity boost we observed. These data add to our understanding of the long-term impacts of fences on wildlife, but also highlight the importance of continued monitoring of confined populations.

scholarly journals Reduced Variation in Drosophila simulans Mitochondrial DNA

Genetics ◽  
1996 ◽  
Vol 144 (4) ◽  
pp. 1519-1528
Author(s):  
J William O Ballad ◽  
Joy Hatzidakis ◽  
Timothy L Karr ◽  
Martin Kreitman
Keyword(s):  
Mitochondrial Dna ◽  
Mitochondrial Genome ◽  
Evolutionary Dynamics ◽  
Selective Sweep ◽  
Mitochondrial Gene ◽  
Drosophila Simulans ◽  
Dramatic Reduction ◽  
Nucleotide Variability ◽  
Pooled Samples ◽  
Mitochondrial Gene Mutation

We investigated the evolutionary dynamics of infection of a Drosophila simulans population by a maternally inherited insect bacterial parasite, Wolbachia, by analyzing nucleotide variability in three regions of the mitochondrial genome in four infected and 35 uninfected lines. Mitochondrial variability is significantly reduced compared to a noncoding region of a nuclear-encoded gene in both uninfected and pooled samples of flies, indicating a sweep of genetic variation. The selective sweep of mitochondrial DNA may have been generated by the fixation of an advantageous mitochondrial gene mutation in the mitochondrial genome. Alternatively, the dramatic reduction in mitochondrial diversity may be related to Wolbachia.

Mitochondrial DNA deletions in the peripheral blood of workers at the Mayak PA who were exposed to long-term combined effects of external γ- and internal α-radiation

BIOPHYSICS ◽  
2016 ◽  
Vol 61 (6) ◽  
pp. 1026-1032
Author(s):  
L. V. Malakhova ◽  
M. G. Lomaeva ◽  
M. L. Zakharova ◽  
E. N. Kirillova ◽  
S. N. Sokolova ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Peripheral Blood ◽  
Combined Effects ◽  
Dna Deletions

Abstract 381: Prolonged Renal Failure Leads to Reduced Number of Active Cardiac Mitochondria in a Rat Model for Long Term Chronic Kidney Disease

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Einat A Hertzberg-Bigelman ◽  
Michal Entin-Meer ◽  
Genya Aharon-Hananel ◽  
Ann Saada ◽  
Ran Levy ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Mitochondrial Dna ◽  
Kidney Disease ◽  
Cardiac Function ◽  
Rat Model ◽  
Dna Content ◽  
Cardiac Mitochondria ◽  
Mitochondrial Content ◽  
Mitochondrial Dna Content

Objectives - Cardiorenal syndrome type 4 is characterized by primary chronic kidney disease (CKD) leading to an impairment of cardiac function. We recently showed a reduced expression of several cardiac mitochondrial genes in short-term CKD rat model. We aimed to evaluate whether cardiac mitochondrial structure and function is modified in long-term CKD and if so, to characterize the potential associated mechanisms. Methods - Lewis rats underwent 5/6 nephrectomy for induction of CKD. Upon necroscopy, eight months later, cardiac sections were analyzed by histology and electron microscopy (EM). Mitochondrial DNA content was determined by the mitochondrial gene, cytochrome B. Mitochondrial content was assessed by citrate synthase (CS) activity in tissue homogenate and respiratory chain function was determined by the activity of complexes I-IV in isolated mitochondria. The levels of PGC1a, a transcription factor for mitochondrial biogenesis, Angiotensin II type 1 receptor and cytosolic cytochrome C were assayed by western blot. Cytokine serum profile was determined by microarray. Results - Long-term CKD leads to cardiac hypertrophy and increased interstitial fibrosis. EM analysis revealed a massive spatial disarrangement accompanied by a considerably increased volume of swollen-damaged mitochondria in CKD hearts (32±3%, n=5, 48±6%, n=4; respectively; p<0.05). Total mitochondrial DNA content was decreased in cardiac tissue of CKD rats. Concomitantly, active mitochondrial content was significantly reduced. Conversely, no differences were observed in respiratory chain enzymes’ functions (complexes I-IV) in isolated active mitochondria. Moreover, inflammatory response and activation of Renin-Angiotensin-Aldosterone-System (RAAS) were detected in the CKD setting. Conclusion - CKD results in a marked reduction of active mitochondria in the heart. Inflammatory cytokines and RAAS, may set a deleterious environment to cardiac mitochondria, as suggested in non-CKD models. The data may represent a significant milestone in the personalized medicine strategy for treating CKD patients who present with normal cardiac function accompanied by positive biomarkers for cardiac mitochondria damage.

scholarly journals Rapid evolution of decreased host susceptibility drives a stable relationship between ultrasmall parasite TM7x and its bacterial host

2018 ◽  
Vol 115 (48) ◽  
pp. 12277-12282 ◽  
Author(s):  
Batbileg Bor ◽  
Jeffrey S. McLean ◽  
Kevin R. Foster ◽  
Lujia Cen ◽  
Thao T. To ◽  
...  
Keyword(s):  
Host Cell ◽  
Rapid Evolution ◽  
Host Population ◽  
Host Cells ◽  
Host Susceptibility ◽  
Bacterial Host ◽  
Narrow Host Range ◽  
Stable Relationship ◽  
Candidate Phyla Radiation

Around one-quarter of bacterial diversity comprises a single radiation with reduced genomes, known collectively as the Candidate Phyla Radiation. Recently, we coisolated TM7x, an ultrasmall strain of the Candidate Phyla Radiation phylum Saccharibacteria, with its bacterial host Actinomyces odontolyticus strain XH001 from human oral cavity and stably maintained as a coculture. Our current work demonstrates that within the coculture, TM7x cells establish a long-term parasitic association with host cells by infecting only a subset of the population, which stay viable yet exhibit severely inhibited cell division. In contrast, exposure of a naïve A. odontolyticus isolate, XH001n, to TM7x cells leads to high numbers of TM7x cells binding to each host cell, massive host cell death, and a host population crash. However, further passaging reveals that XH001n becomes less susceptible to TM7x over time and enters a long-term stable relationship similar to that of XH001. We show that this reduced susceptibility is driven by rapid host evolution that, in contrast to many forms of phage resistance, offers only partial protection. The result is a stalemate where infected hosts cannot shed their parasites; nevertheless, parasite load is sufficiently low that the host population persists. Finally, we show that TM7x can infect and form stable long-term relationships with other species in a single clade of Actinomyces, displaying a narrow host range. This system serves as a model to understand how parasitic bacteria with reduced genomes such as those of the Candidate Phyla Radiation have persisted with their hosts and ultimately expanded in their diversity.

scholarly journals Preparation of mitochondrial DNA from long-term preserved and accident carcass organs in animals.

1994 ◽  
Vol 38 (1) ◽  
pp. 19-23
Author(s):  
Michinari Yokohama ◽  
Taisuke Yamazaki ◽  
Yuichi Kameyama ◽  
Yoshirou Ishijima
Keyword(s):  
Mitochondrial Dna

scholarly journals Tracking mitochondrial density and positioning along a growing neuronal process in individual C. elegans neuron using a long-term growth and imaging microfluidic device

eNeuro ◽  
2021 ◽  
pp. ENEURO.0360-20.2021
Author(s):  
Sudip Mondal ◽  
Jyoti Dubey ◽  
Anjali Awasthi ◽  
Guruprasad Reddy Sure ◽  
Amruta Vasudevan ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
Mitochondrial Density ◽  
Neuronal Process ◽  
C Elegans

Bernstein’s Philosophy and the Language of Jazz

2019 ◽  
pp. 11-44
Author(s):  
Katherine Baber
Keyword(s):  
National Identity ◽  
Unanswered Question ◽  
Human Communication ◽  
Musical Meaning ◽  
Unique Form ◽  
Musical Identity ◽  
Musical Thinking ◽  
Definition Of

Chapter 1 looks at Bernstein’s writings on musical meaning, national style, and jazz to reveal the philosophy behind his use of jazz and its significance as a part of his long-term project to define American musical identity. A definition of the jazz idiom, according to Bernstein’s understanding, is interwoven with three important strands of Bernstein’s musical thinking: the primacy of tonality, the value of music as a unique form of human communication, and the formation of national identity in music. The chapter focuses particularly on Bernstein’s Harvard honors thesis, the Charles Eliot Norton Lectures (published as The Unanswered Question), and The Joy of Music.

scholarly journals An antimicrobial peptide essential for bacterial survival in the nitrogen-fixing symbiosis

2015 ◽  
Vol 112 (49) ◽  
pp. 15238-15243 ◽  
Author(s):  
Minsoo Kim ◽  
Yuhui Chen ◽  
Jiejun Xi ◽  
Christopher Waters ◽  
Rujin Chen ◽  
...  
Keyword(s):  
Host Cells ◽  
Marker Genes ◽  
Bacterial Survival ◽  
Nitrogen Fixing ◽  
Term Survival ◽  
Model Legume ◽  
Bacterial Differentiation ◽  
Peribacteroid Space ◽  
Intracellular Organelles

In the nitrogen-fixing symbiosis between legume hosts and rhizobia, the bacteria are engulfed by a plant cell membrane to become intracellular organelles. In the model legume Medicago truncatula, internalization and differentiation of Sinorhizobium (also known as Ensifer) meliloti is a prerequisite for nitrogen fixation. The host mechanisms that ensure the long-term survival of differentiating intracellular bacteria (bacteroids) in this unusual association are unclear. The M. truncatula defective nitrogen fixation4 (dnf4) mutant is unable to form a productive symbiosis, even though late symbiotic marker genes are expressed in mutant nodules. We discovered that in the dnf4 mutant, bacteroids can apparently differentiate, but they fail to persist within host cells in the process. We found that the DNF4 gene encodes NCR211, a member of the family of nodule-specific cysteine-rich (NCR) peptides. The phenotype of dnf4 suggests that NCR211 acts to promote the intracellular survival of differentiating bacteroids. The greatest expression of DNF4 was observed in the nodule interzone II-III, where bacteroids undergo differentiation. A translational fusion of DNF4 with GFP localizes to the peribacteroid space, and synthetic NCR211 prevents free-living S. meliloti from forming colonies, in contrast to mock controls, suggesting that DNF4 may interact with bacteroids directly or indirectly for its function. Our findings indicate that a successful symbiosis requires host effectors that not only induce bacterial differentiation, but also that maintain intracellular bacteroids during the host–symbiont interaction. The discovery of NCR211 peptides that maintain bacterial survival inside host cells has important implications for improving legume crops.

scholarly journals Plasmid-Based shRNA Lentiviral Particle Production for RNAi Applications

2014 ◽  
Vol 19 (9) ◽  
pp. 1309-1313 ◽  
Author(s):  
David Shum ◽  
Hakim Djaballah
Keyword(s):  
Particle Production ◽  
High Titer ◽  
Cell Types ◽  
Host Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Hairpin Rna ◽  
Double Stranded Rna ◽  
Rna Molecules ◽  
Overall Efficiency

Lentiviral vectors have become mainstream gene transfer vehicles for their ability to deliver and integrate into host cells. In RNA interference (RNAi) applications, lentiviral constructs constitutively express double-stranded RNA molecules, usually as short hairpin RNA (shRNA), enabling long-term gene silencing, and, when pseudotyped with a broad host glycoprotein envelope, allow a multitude of cell types to be transduced. Their successful use ultimately relies on the production of lentiviral particles in high titer and uniformity. Typical methods require the transfection of three or more plasmids in which essential viral elements have been encoded separated so as to remain replication deficient. These transfection procedures are of critical importance; however, methods often vary among laboratories, making it difficult to assess the overall efficiency of lentiviral particle production. In this report, we focus exclusively on this step and compare the overall impact of the commercial transfection reagent FuGENE 6 with FuGENE HD. We found that FuGENE HD resulted in at least 5-fold improvement in viral particle titer as assessed by the p24 standard enzyme-linked immunosorbent assay. We present the complete optimized workflow and demonstrate this utility in which a single modification of this transfection step improved the lentiviral particle production.

Sign in / Sign up

Export Citation Format

Share Document