scholarly journals Prevalence and relationship of endosymbiotic Wolbachia in the butterfly genus Erebia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kay Lucek ◽  
Selim Bouaouina ◽  
Amanda Jospin ◽  
Andrea Grill ◽  
Jurriaan M. de Vos
Keyword(s):  
Host Species ◽  
Population Level ◽  
Genetic Data ◽  
Glacial Refugia ◽  
Geographic Proximity ◽  
Host Shifts ◽  
Complex Interactions ◽  
Multiple Processes ◽  
Relationship Of ◽  
Diversification Pattern

Abstract Background Wolbachia is an endosymbiont common to most invertebrates, which can have significant evolutionary implications for its host species by acting as a barrier to gene flow. Despite the importance of Wolbachia, still little is known about its prevalence and diversification pattern among closely related host species. Wolbachia strains may phylogenetically coevolve with their hosts, unless horizontal host-switches are particularly common. We address  these issues in the genus Erebia, one of the most diverse Palearctic butterfly genera. Results We sequenced the Wolbachia genome from a strain infecting Erebia cassioides and showed that it belongs to the Wolbachia supergroup B, capable of infecting arthropods from different taxonomic orders. The prevalence of Wolbachia across 13 closely related Erebia host species based on extensive population-level genetic data revealed that multiple Wolbachia strains jointly infect all investigated taxa, but with varying prevalence. Finally, the phylogenetic relationships of Wolbachia strains are in some cases significantly associated to that of their hosts, especially among the most closely related Erebia species, demonstrating mixed evidence for phylogenetic coevolution. Conclusions Closely related host species can be infected by closely related Wolbachia strains, evidencing some phylogenetic coevolution, but the actual pattern of infection more often reflects historical or contemporary geographic proximity among host species. Multiple processes, including survival in distinct glacial refugia, recent host shifts in sympatry, and a loss of Wolbachia during postglacial range expansion seem to have jointly shaped the complex interactions between Wolbachia evolution and the diversification of its host among our studied Erebia species.

scholarly journals Virulence mismatches in index hosts shape the outcomes of cross-species transmission

2020 ◽  
Vol 117 (46) ◽  
pp. 28859-28866 ◽  
Author(s):  
Nardus Mollentze ◽  
Daniel G. Streicker ◽  
Pablo R. Murcia ◽  
Katie Hampson ◽  
Roman Biek
Keyword(s):  
Rabies Virus ◽  
Host Species ◽  
Single Infection ◽  
Limiting Factor ◽  
New Host ◽  
Host Shifts ◽  
Complex Interactions ◽  
Dead End ◽  
Novel Host ◽  
Meta Analyses

Whether a pathogen entering a new host species results in a single infection or in onward transmission, and potentially an outbreak, depends upon the progression of infection in the index case. Although index infections are rarely observable in nature, experimental inoculations of pathogens into novel host species provide a rich and largely unexploited data source for meta-analyses to identify the host and pathogen determinants of variability in infection outcomes. We analyzed the progressions of 514 experimental cross-species inoculations of rabies virus, a widespread zoonosis which in nature exhibits both dead-end infections and varying levels of sustained transmission in novel hosts. Inoculations originating from bats rather than carnivores, and from warmer- to cooler-bodied species caused infections with shorter incubation periods that were associated with diminished virus excretion. Inoculations between distantly related hosts tended to result in shorter clinical disease periods, which are also expected to impede onward transmission. All effects were modulated by infection dose. Taken together, these results suggest that as host species become more dissimilar, increased virulence might act as a limiting factor preventing onward transmission. These results can explain observed constraints on rabies virus host shifts, describe a previously unrecognized role of host body temperature, and provide a potential explanation for host shifts being less likely between genetically distant species. More generally, our study highlights meta-analyses of experimental infections as a tractable approach to quantify the complex interactions between virus, reservoir, and novel host that shape the outcome of cross-species transmission.

scholarly journals Investigating hot-Jupiter inflated radii with hierarchical Bayesian modelling

2018 ◽  
Vol 616 ◽  
pp. A76 ◽  
Author(s):  
Marko Sestovic ◽  
Brice-Olivier Demory ◽  
Didier Queloz
Keyword(s):  
Large Fraction ◽  
Population Level ◽  
Mass Range ◽  
Hierarchical Bayesian ◽  
Incident Flux ◽  
Hot Jupiters ◽  
Probabilistic Relation ◽  
Relationship Of ◽  
The Relationship ◽  
Level Analysis

Context. As of today, hundreds of hot Jupiters have been found, yet the inflated radii of a large fraction of them remain unexplained. A number of mechanisms have been proposed to explain these anomalous radii, however most of these can only work under certain conditions and may not be sufficient to explain the most extreme cases. It is still unclear whether a single mechanism can sufficiently explain the entire distribution of radii, or whether a combination of these mechanisms is needed. Aims. We seek to understand the relationship of radius with stellar irradiation and mass and to find the range of masses over which hot Jupiters are inflated. We also aim to find the intrinsic physical scatter in their radii, caused by unobservable parameters, and to constrain the fraction of hot Jupiters that exhibit inflation. Methods. By constructing a hierarchical Bayesian model, we inferred the probabilistic relation between planet radius, mass, and incident flux for a sample of 286 gas giants. We separately incorporated the observational uncertainties of the data and the intrinsic physical scatter in the population. This allowed us to treat the intrinsic physical scatter in radii, due to latent parameters such as the heavy element fraction, as a parameter to be inferred. Results. We find that the planetary mass plays a key role in the inflation extent and that planets in the range ~0.37−0.98  MJ show the most inflated radii. At higher masses, the radius response to incident flux begins to decrease. Below a threshold of 0.37 ± 0.03  MJ we find that giant exoplanets as a population are unable to maintain inflated radii ≿1.4  RJ but instead exhibit smaller sizes as the incident flux is increased beyond 106 W m−2. We also find that below 1  MJ, there is a cut-off point at high incident flux beyond which we find no more inflated planets, and that this cut-off point decreases as the mass decreases. At incident fluxes higher than ~1.6 × 106 W m−2 and in a mass range 0.37−0.98  MJ, we find no evidence for a population of non-inflated hot Jupiters. Our study sheds a fresh light on one of the key questions in the field and demonstrates the importance of population-level analysis to grasp the underlying properties of exoplanets.

scholarly journals Systems analysis – complex interactions of factors that influence the sustainability of access to improved water services in a rural municipality in South Africa

2021 ◽  
Author(s):  
Calvin Sambo ◽  
Aidan Senzanje ◽  
Mutanga Onisimo
Keyword(s):  
South Africa ◽  
Rural Communities ◽  
Rural Livelihoods ◽  
Water Services ◽  
Critical Factors ◽  
Rural Municipality ◽  
Effect Relationship ◽  
Complex Interactions ◽  
Limited Budget ◽  
Relationship Of

Abstract Limited understanding of the complex interactions of factors that influence the sustainability of access to improved water services poses a threat to rural livelihoods. The study assessed the complex interactions of the factors using a network approach. The assessment was to understand the complex interaction of the factors resulting from their cause-effect relationship that influence the sustainability of access to improved water services in a rural municipality of South Africa. The results highlighted that limited budget, limited or no water supply and improper operation and maintenance were critical factors resulting from the cause-effect relationship of other factors that influenced the sustainability of access to improved water services in the study area. We conclude that critical factors with a cause-effect relationship can influence the sustainability of access to improved water services. As a result, this deprives rural communities of the benefits derived from accessing improved water services. We recommend the use of the findings by the relevant authorities responsible for water services provision to inform planning, management, policies to address challenges identified to contribute to sustainability of access to improved water services.

scholarly journals Rapid divergence in independent aspects of the compatibility phenotype in the Spiroplasma/Drosophila interaction

2021 ◽  
Author(s):  
Joanne S. Griffin ◽  
Michael Gerth ◽  
Gregory D. D. Hurst
Keyword(s):  
Vertical Transmission ◽  
Host Species ◽  
High Efficiency ◽  
Host Shift ◽  
Direct Selection ◽  
New Host ◽  
Host Shifts ◽  
Species Pairs ◽  
Novel Host ◽  
Rapid Divergence

AbstractHeritable symbionts represent important components of host biology, both as antagonistic reproductive parasites and as beneficial protective partners. An important component of heritable microbes’ biology is their ability to establish in new host species, a process equivalent to a host shift for an infectiously transmitted parasite or pathogen. For a host shift to occur, the symbiont must be compatible with the host: it must not cause excess pathology, must have good vertical transmission, and possess a drive phenotype that enables spread. Classically, compatibility has been considered a declining function of genetic distance between novel and ancestral host species. Here we investigate the evolutionary lability of compatibility to heritable microbes by comparing the capacity for a symbiont to establish in two novel host species equally related to the ancestral host. Compatibility of the protective Spiroplasma from D. hydei with D. simulans and D. melanogaster was tested. The Spiroplasma had contrasting compatibility in these two host species. The transinfection showed pathology and low vertical transmission in D. melanogaster but was asymptomatic and transmitted with high efficiency in D. simulans. These results were not affected by the presence/absence of Wolbachia in either of the two species. The pattern of protection was not congruent with that for pathology/transmission, with protection being weaker in the D. simulans, the host in which Spiroplasma was asymptomatic and transmitted well. Further work indicated pathological interactions occurred in D. sechellia and D. yakuba, indicating that D. simulans was unusual in being able to carry the symbiont without damage. The differing compatibility of the symbiont with these closely related host species emphasises first the rapidity with which host-symbiont compatibility evolves despite compatibility itself not being subject to direct selection, and second the independence of the different components of compatibility (pathology, transmission, protection). This requirement to fit three different independently evolving aspects of compatibility, if commonly observed, is likely to be a major feature limiting the rate of host shifts. Moving forward, the variation between sibling species pairs observed above provides an opportunity to identify the mechanisms behind variable compatibility between closely related host species, which will drive hypotheses as to the evolutionary drivers of compatibility variation.

scholarly journals Evidence for Multiple Recent Host Species Shifts among the Ranaviruses (Family Iridoviridae)

2009 ◽  
Vol 84 (6) ◽  
pp. 2636-2647 ◽  
Author(s):  
James K. Jancovich ◽  
Michel Bremont ◽  
Jeffrey W. Touchman ◽  
Bertram L. Jacobs
Keyword(s):  
Host Species ◽  
Fish Pathogen ◽  
Necrosis Virus ◽  
Viral Pathogens ◽  
Host Shifts ◽  
Fish Virus ◽  
New Hosts ◽  
Australian Fish ◽  
Species Shifts

ABSTRACT Members of the genus Ranavirus (family Iridoviridae) have been recognized as major viral pathogens of cold-blooded vertebrates. Ranaviruses have been associated with amphibians, fish, and reptiles. At this time, the relationships between ranavirus species are still unclear. Previous studies suggested that ranaviruses from salamanders are more closely related to ranaviruses from fish than they are to ranaviruses from other amphibians, such as frogs. Therefore, to gain a better understanding of the relationships among ranavirus isolates, the genome of epizootic hematopoietic necrosis virus (EHNV), an Australian fish pathogen, was sequenced. Our findings suggest that the ancestral ranavirus was a fish virus and that several recent host shifts have taken place, with subsequent speciation of viruses in their new hosts. The data suggesting several recent host shifts among ranavirus species increase concern that these pathogens of cold-blooded vertebrates may have the capacity to cross numerous poikilothermic species barriers and the potential to cause devastating disease in their new hosts.

Relationship of Area-Level Socioeconomic Status Indicators and Nutritional Anemias: Analysis of Folate, Vitamin B12, and Iron Deficiencies

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 16-17
Author(s):  
Miguel Gonzalez Velez ◽  
Carolyn Mead-Harvey ◽  
Heidi E. Kosiorek ◽  
Yael Kusne ◽  
Leyla Bojanini ◽  
...  
Keyword(s):  
Socioeconomic Status ◽  
Vitamin B12 ◽  
Conflicts Of Interest ◽  
Population Level ◽  
Serum Folate ◽  
Continuous Variables ◽  
Cross Sectional ◽  
The Us ◽  
Relationship Of ◽  
The Relationship

Introduction: Serum folate (SF), vitamin B12 (B12), and iron deficiency (def) are common causes of nutritional anemias (NA). These deficiencies are usually multifactorial, with nutritional and non-nutritional causes playing a role. SF, B12, and iron levels are usually ordered in the setting of anemia, and malnutrition with or without neurologic symptoms. Clinical evidence suggests that these def have a strong dietary component and socioeconomic status (SES). The relationship of NA and area-based SES in the US has not been studied. We aimed to determine the relationship of SES with the prevalence of NA. Methods: We performed a cross-sectional analysis of adult patients with SF, B12 and iron levels at Mayo Clinic Arizona and Florida between 2010 and 2018. Race was classified using the NIH criteria. Normal laboratory values were determined according to our lab reference and the US NHANES III. SF levels (mcg/Lt) were defined as deficient <4, normal ≥4.0, and excess ≥20. B12 levels (ng/L) as deficient <150, borderline 150-400, normal >400-900, and excess ≥900. Iron def was determined by ferritin levels (mcg/L) as low <24, normal 24-336, elevated >336 for men, low <11, normal 11-307, elevated >307 for women. Area-Level SES indicators: Median Household income (MHI), unemployment rate (UR), median gross rent month (MGRM), % uninsured, median house value (MHV), % high school; were geocoded by zip code using the 2014 American Community Survey. Demographics and clinical variables were compared between groups by chi-square test for frequency data or Kruskal Wallis rank-sum test for continuous variables. Results: 202,046 samples from 128,084 patients were analyzed. In the sample-level analysis, there were statistically significant associations between SES and SF def; all SES indicators except UR for B12 def; and no differences for iron def, except % uninsured (Table 1). There was no statistically significant interaction between race and SES for SF def and iron def. Race was a statistically significant modifier between B12 def and MHI (p<0.001), % uninsured (p=0.002), and MHV (p=0.007). Asian and Other race had an increase in odds of B12 def with increasing MHI (Asian OR=1.11 , Other OR=1.18); white race had a decrease in odds of B12 def with increasing MHI (OR=0.95 for a $10,000 increase in MHI). Conclusions: We show significant relationships between SES and NA in the US. Differences were observed between SF def and all the SES indicators without race interactions. There were significant interactions between B12 def, race and SES for pts of White, Asian and Other race. There were no differences between SES and race for iron def. These relationships confirm that NA are related to area-level SES and other social determinants of health. Research regarding the causes of these disparities on a population level are needed. Disclosures No relevant conflicts of interest to declare.

scholarly journals Characterization of the β-lactamase specified by the resistance factor R-1818 in Escherichia coli K12 and other Gram-negative bacteria

1971 ◽  
Vol 123 (4) ◽  
pp. 501-505 ◽  
Author(s):  
J. W. Dale
Keyword(s):  
Escherichia Coli ◽  
Host Species ◽  
Host Bacterium ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
R Factor ◽  
Relationship Of ◽  
The Relationship

1. The amino acid composition of the β-lactamase from E. coli (R-1818) was determined. 2. The R-1818 β-lactamase is inhibited by formaldehyde, hydroxylamine, sodium azide, iodoacetamide, iodine and sodium chloride. 3. The Km values for benzylpenicillin, ampicillin and oxacillin have been determined by using the R-factor enzyme from different host species. The same values were obtained, irrespective of the host bacterium. 4. The molecular weight of the enzyme was found to be 44600, and was the same for all host species. 5. The relationship of R-1818 and R-GN238 β-lactamases is discussed.

Certain aspects of the host-parasite relationship of Nematospiroides dubius (Baylis): V. Host specificity

Parasitology ◽  
1962 ◽  
Vol 52 (1-2) ◽  
pp. 41-48 ◽  
Author(s):  
Colin Dobson
Keyword(s):  
Host Specificity ◽  
Host Species ◽  
Adult Parasite ◽  
Male Rat ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
Nematospiroides Dubius ◽  
Host Parasite ◽  
Relationship Of

1. The mouse is more susceptible to infection than the rat.2. The male in both the rat and the mouse is more susceptible to infection than the female.3. The development of the worm is slower in the male rat than in the female. This relationship does not occur in the mouse.4. The ecological position of the adult parasite was different in the mouse and rat, the worms living further down the intestine in the rat.5. The effects of host species on infection of N. dubius are discussed.

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