scholarly journals Host Genotype and Precipitation Influence of Fungal Endophyte Symbiosis and Mycotoxin Abundance in a Locoweed

2019 ◽  
Vol 20 (21) ◽  
pp. 5285
Author(s):  
Wei He ◽  
Linwei Guo ◽  
Lei Wang ◽  
Qianqian Zhao ◽  
Lizhu Guo ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Geographical Location ◽  
Population Level ◽  
Fungal Endophyte ◽  
Host Population ◽  
Host Genotype ◽  
Symbiotic Interactions ◽  
Naturally Occurring ◽  
Endophyte Infection ◽  
Host Genetic

Many plant endophytes produce mycotoxins, but how host genetic variation influences endophyte colonization and mycotoxin production under natural conditions is poorly understood. This interaction has not been fully considered in many previous studies which used controlled experiments with agronomic or model plant species. Here, we investigated this interaction in a naturally occurring forb (a locoweed species) Oxytropis ochrocephala, its symbiotic endophyte Alternaria oxytropis, and the mycotoxin swainsonine. Host genetic variation was characterized by microsatellite markers. Endophyte infection rate and swainsonine levels were determined by PCR and HPLC, respectively. Genetic markers defined two distinct host populations and revealed that host genetics were significantly correlated with geographical location, elevation, and precipitation. As the host diverged, symbiotic interactions were reduced or failed to produce detectable swainsonine in one host population. Host genotype and precipitation had a significant impact in shaping swainsonine production at the population level. This study highlights the effect of host genotype in influencing this interaction in locoweeds.

scholarly journals Community assembly in plant-bacterium symbiotic interactions in a natural environment: Does host genetic variation matter?

2021 ◽  
Author(s):  
Shinnosuke Kagiya ◽  
Ken-ichi Kucho ◽  
Shunsuke Utsumi
Keyword(s):  
Genetic Variation ◽  
Community Assembly ◽  
Community Analysis ◽  
Interaction Networks ◽  
Natural Environments ◽  
Ecological Communities ◽  
Natural Ecosystems ◽  
Symbiotic Interactions ◽  
Host Genetic

Community assembly of diverse mutualistic symbionts in host plants have recently received much attention. On the other hand, for decades, researchers have also focused on a role of genetic variation for shaping ecological communities. However, it remains unclear how local interaction networks between a host and symbionts are shaped from the pool of genetically diverse microorganisms in the natural rhizosphere. In this study, we comprehensively analyzed local and regional genetic communities of Frankia in host individuals and in surrounding soils using metabarcoding to unravel community assembly in shaping interaction networks between plants and root nodule symbionts, both of which are genetically diverse, in natural ecosystems. We found that Frankia communities in rhizosphere soil were consisted of tremendously diverse strains. The diverse Frankia communities in rhizosphere soils were heterogeneously structured by the presence of host individuals and soil nutritional status. Furthermore, quantification of the filtering forces by community analysis demonstrated that the filtering forces that shape symbiotic networks would depend on genetic variation in the host plant. This study suggests that filtering mechanisms and host genetics would have a profound role in shaping plant-bacterium symbiotic networks in natural environments.

scholarly journals Population bottlenecks constrain microbiome diversity and host genetic variation impeding fitness

2021 ◽  
Author(s):  
Michael Oersted ◽  
Erika Yashiro ◽  
Ary A Hoffmann ◽  
Torsten Nygaard Kristensen
Keyword(s):  
Genetic Variation ◽  
Microbial Diversity ◽  
Focal Point ◽  
Host Population ◽  
Rrna Gene ◽  
Population Bottlenecks ◽  
Biodiversity Crisis ◽  
Microbiome Diversity ◽  
Host Genetic ◽  
Microbial Symbionts

It is becoming increasingly clear that microbial symbionts influence key aspects of their host's fitness, and vice versa. This may fundamentally change our thinking about how microbes and hosts interact in influencing fitness and adaptation to changing environments. Here we explore how reductions in population size commonly experienced by threatened species influence microbiome diversity. Fitness consequences of such reductions are normally interpreted in terms of a loss of genetic variation and increase in inbreeding depression due to a loss of heterozygosity. However, fitness effects might also be mediated through microbiome diversity, e.g. if functionally important microbes are lost. Here we utilise Drosophila melanogaster lines with different histories of population bottlenecks to explore these questions. The lines were phenotyped for egg-to-adult viability and their genomes sequenced to estimate genetic variation. The bacterial 16S rRNA gene was amplified in these lines to investigate microbial diversity. We found that 1) host population bottlenecks constrained microbiome richness and diversity, 2) core microbiomes of hosts with low genetic variation were constituted from subsets of microbiomes found in flies with higher genetic variation, 3) both microbiome diversity and host genetic variation contributed to host population fitness, 4) connectivity and robustness of bacterial networks increased with higher host genetic variation, and 5) reduced microbial diversity is associated with weaker evolutionary responses in stressful environments. These findings suggest that population bottlenecks reduce hologenomic variation (in combined host and microbial genomes). Thus while the current biodiversity crisis focuses on population sizes and genetic variation of eukaryotes, an additional focal point should be the microbial diversity carried by the eukaryotes, which in turn may influence host fitness and adaptability with consequences for the persistence of populations.

scholarly journals Multivariate Abundance Analysis of Multi-Host/Multi-Parasite Lungworms in a Sympatric Wild Ruminant Population

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 227
Author(s):  
Tessa Carrau ◽  
Carlos Martínez-Carrasco ◽  
María Magdalena Garijo ◽  
Francisco Alonso ◽  
Rocío Ruiz de Ybáñez ◽  
...  
Keyword(s):  
Population Level ◽  
Parasite Load ◽  
Fallow Deer ◽  
Host Population ◽  
Marginal Effect ◽  
Wild Ruminant ◽  
Additional Species ◽  
Parasite Abundance ◽  
Associated Risk Factors ◽  
Natural Dynamics

In the analysis of a multi-host/multi-parasite system and its associated risk factors, it is particularly interesting to understand the natural dynamics among pathogens, their hosts, and the environment in wildlife populations. This analysis is particularly feasible in a scenario where multiple overlapping host populations are present in high densities, along with a complex community of parasites. We aimed to describe and analyze the naturally occurring lungworm polyparasitism in a wild ruminant community in Southeast Spain. The respiratory tracts of 250 specimens belonging to four different species (red deer, mouflon, Iberian ibex, and fallow deer) were studied. Almost half (48.0%) of the animals were infected with bronchopulmonary nematodes. Seven different nematodes were identified of which two genera (Protostrongylus spp. and Dictyocaulus spp.) and three additional species (Cystocaulus ocreatus, Muellerius capillaris, and Neostrongylus linearis) were recorded in at least two ruminants, with the mouflon as the commonest host. Our study shows a significant effect of host species and sampling area, plus a marginal effect of age, on parasite multivariate abundance at the host population level. Mouflon and adults of all hosts appear to carry the highest parasite load on average. From a spatial perspective, the highest parasite abundance was detected at the central part of the park.

Prejudicial reactions to the removal of Native American mascots

2021 ◽  
pp. 136843022110408
Author(s):  
Tyler Jimenez ◽  
Jamie Arndt ◽  
Peter J. Helm
Keyword(s):  
Native American ◽  
Native Americans ◽  
Intergroup Relations ◽  
Psychological Impact ◽  
Geographical Location ◽  
Population Level ◽  
Location Study ◽  
Chief Illiniwek ◽  
The Impact ◽  
Chief Wahoo

As Native American mascots are discontinued, research is needed to understand the impact on intergroup relations. Such discontinuations may be threatening to some and increase prejudice against Native Americans. In Study 1 ( N = 389), exposure to information about a Native American mascot removal increased punitive judgments against a Native American in a hypothetical legal scenario, particularly among those high in racial colorblindness and those residing in the implicated geographical location. Study 2 ( N = 358,644) conceptually replicated and extended these findings, using population-level implicit bias data to perform a natural quasi-experiment. Prejudice against Native Americans increased in the year following the removal of two Native American mascots: “Chief Illiniwek” and “Chief Wahoo.” However, in the case of Chief Illiniwek, the effect diminished after 6 years. Together, the studies contribute to understanding the psychological impact of Native American mascots, offering a first look at how their removal influence intergroup relations.

scholarly journals Parasite variation and the evolution of virulence in a Daphnia-microparasite system

Parasitology ◽  
2007 ◽  
Vol 135 (3) ◽  
pp. 303-308 ◽  
Author(s):  
T. J. LITTLE ◽  
W. CHADWICK ◽  
K. WATT
Keyword(s):  
Genetic Variation ◽  
Rank Order ◽  
Genetic Relationships ◽  
Natural Populations ◽  
Host Genotype ◽  
Relative Growth ◽  
Trade Off ◽  
Relative Growth Rates ◽  
Pasteuria Ramosa ◽  
Evolution Of Virulence

SUMMARYUnderstanding genetic relationships amongst the life-history traits of parasites is crucial for testing hypotheses on the evolution of virulence. This study therefore examined variation between parasite isolates (the bacterium Pasteuria ramosa) from the crustacean Daphnia magna. From a single wild-caught infected host we obtained 2 P. ramosa isolates that differed substantially in the mortality they caused. Surprisingly, the isolate causing higher early mortality was, on average, less successful at establishing infections and had a slower growth rate within hosts. The observation that within-host replication rate was negatively correlated with mortality could violate a central assumption of the trade-off hypothesis for the evolution of virulence, but we discuss a number of caveats which caution against premature rejection of the trade-off hypothesis. We sought to test if the characteristics of these parasite isolates were constant across host genotypes in a second experiment that included 2 Daphnia host clones. The relative growth rates of the two parasite isolates did indeed depend on the host genotype (although the rank order did not change). We suggest that testing evolutionary hypotheses for virulence may require substantial sampling of both host and parasite genetic variation, and discuss how selection for virulence may change with the epidemiological state of natural populations and how this can promote genetic variation for virulence.

Low diversity and high intra-island variation in prevalence of avian Haemoproteus parasites on Barbados, Lesser Antilles

Parasitology ◽  
2009 ◽  
Vol 136 (10) ◽  
pp. 1121-1131 ◽  
Author(s):  
L. MARIA ◽  
E. SVENSSON ◽  
ROBERT E. RICKLEFS
Keyword(s):  
Bird Species ◽  
Host Population ◽  
Genetic Differences ◽  
Haemosporidian Parasite ◽  
Pcr Screening ◽  
Limited Sampling ◽  
Haemosporidian Parasites ◽  
Free Region ◽  
Host Genetic ◽  
Coereba Flaveola

SUMMARYCommon bird species were screened during May and June 2007 on Barbados for haemosporidian parasites (Haemosporida) of the genera Haemoproteus and Plasmodium to determine whether the low parasite diversity reported in previous studies might have reflected limited sampling. PCR screening and DNA sequencing revealed a single predominant lineage of Haemoproteus identified as H. coatneyi. Sixty-two out of 257 birds were infected with Haemoproteus spp. on Barbados in 2007. Fifty-nine of the infections were identified as H. coatneyi (lineage HC), the only lineage recovered in the previous study in 1993. Two of the infections recovered from the bananaquit (Coereba flaveola) were identified as Haemoproteus spp. (lineage HD), which is the prevalent haemosporidian parasite in C. flaveola on Grenada. We discuss the possibility of infrequent colonization events and absence of vectors as explanations for Barbados's low avian haemosporidian diversity. In our study, the parasites were absent from the southeast of the island, whereas they were abundant in several host species in the northwest. Accordingly, environmental and host population genetic differences were also investigated between the areas with and without parasites. No host genetic differences were found between the parasite-free and the parasite-afflicted regions. However, the parasite-free region is slightly warmer and drier, and it supports less vegetation than the parasite-afflicted region. The influence that this harsher environment may have on vector survival is discussed.

Sign in / Sign up

Export Citation Format

Share Document