14 research outputs found

    Effect of spatial connectivity on host resistance in a highly fragmented natural pathosystem

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    Both theory and experimental evolution studies predict migration to influence the outcome of antagonistic coevolution between hosts and their parasites, with higher migration rates leading to increased diversity and evolutionary potential. Migration rates are expected to vary in spatially structured natural pathosystems, yet how spatial structure generates variation in coevolutionary trajectories across populations occupying the same landscape has not been tested. Here, we studied the effect of spatial connectivity on host evolutionary potential in a natural pathosystem characterized by a stable Plantago lanceolata host network and a highly dynamic Podosphaera plantaginis parasite metapopulation. We designed a large inoculation experiment to test resistance of five isolated and five well-connected host populations against sympatric and allopatric pathogen strains, over 4years. Contrary to our expectations, we did not find consistently higher resistance against sympatric pathogen strains in the well-connected populations. Instead, host local adaptation varied considerably among populations and through time with greater fluctuations observed in the well-connected populations. Jointly, our results suggest that in populations where pathogens have successfully established, they have the upper hand in the coevolutionary arms race, but hosts may be better able to respond to pathogen-imposed selection in the well-connected than in the isolated populations. Hence, the ongoing and extensive fragmentation of natural habitats may increase vulnerability to diseases.Peer reviewe

    Spatially structured eco-evolutionary dynamics in a host-pathogen interaction render isolated populations vulnerable to disease

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    While the negative effects that pathogens have on their hosts are well-documented in humans and agricultural systems, direct evidence of pathogen-driven impacts in wild host populations is scarce and mixed. Here, to determine how the strength of pathogen-imposed selection depends on spatial structure, we analyze growth rates across approximately 4000 host populations of a perennial plant through time coupled with data on pathogen presence-absence. We find that infection decreases growth more in the isolated than well-connected host populations. Our inoculation study reveals isolated populations to be highly susceptible to disease while connected host populations support the highest levels of resistance diversity, regardless of their disease history. A spatial eco-evolutionary model predicts that non-linearity in the costs to resistance may be critical in determining this pattern. Overall, evolutionary feedbacks define the ecological impacts of disease in spatially structured systems with host gene flow being more important than disease history in determining the outcome

    Spatially structured eco-evolutionary dynamics in a host-pathogen interaction render isolated populations vulnerable to disease

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    While the negative effects that pathogens have on their hosts are well-documented in humans and agricultural systems, direct evidence of pathogen-driven impacts in wild host populations is scarce and mixed. Here, to determine how the strength of pathogen-imposed selection depends on spatial structure, we analyze growth rates across approximately 4000 host populations of a perennial plant through time coupled with data on pathogen presence-absence. We find that infection decreases growth more in the isolated than well-connected host populations. Our inoculation study reveals isolated populations to be highly susceptible to disease while connected host populations support the highest levels of resistance diversity, regardless of their disease history. A spatial eco-evolutionary model predicts that non-linearity in the costs to resistance may be critical in determining this pattern. Overall, evolutionary feedbacks define the ecological impacts of disease in spatially structured systems with host gene flow being more important than disease history in determining the outcome.Peer reviewe

    Genotype-Specific Expression and NLR Repertoire Contribute to Phenotypic Resistance Diversity in Plantago lanceolata

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    Publisher Copyright: © Copyright © 2021 Safdari, Höckerstedt, Brosche, Salojärvi and Laine.High levels of phenotypic variation in resistance appears to be nearly ubiquitous across natural host populations. Molecular processes contributing to this variation in nature are still poorly known, although theory predicts resistance to evolve at specific loci driven by pathogen-imposed selection. Nucleotide-binding leucine-rich repeat (NLR) genes play an important role in pathogen recognition, downstream defense responses and defense signaling. Identifying the natural variation in NLRs has the potential to increase our understanding of how NLR diversity is generated and maintained, and how to manage disease resistance. Here, we sequenced the transcriptomes of five different Plantago lanceolata genotypes when inoculated by the same strain of obligate fungal pathogen Podosphaera plantaginis. A de novo transcriptome assembly of RNA-sequencing data yielded 24,332 gene models with N50 value of 1,329 base pairs and gene space completeness of 66.5%. The gene expression data showed highly varying responses where each plant genotype demonstrated a unique expression profile in response to the pathogen, regardless of the resistance phenotype. Analysis on the conserved NB-ARC domain demonstrated a diverse NLR repertoire in P. lanceolata consistent with the high phenotypic resistance diversity in this species. We find evidence of selection generating diversity at some of the NLR loci. Jointly, our results demonstrate that phenotypic resistance diversity results from a crosstalk between different defense mechanisms. In conclusion, characterizing the architecture of resistance in natural host populations may shed unprecedented light on the potential of evolution to generate variation.Peer reviewe

    An Aesthetic Factor Priority List of the Female Breast in Scandinavian Subjects

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    Background: There is little consensus about the relative determinative value of each individual factor in female breast aesthetics. When performing breast surgery with an aesthetic goal, certain factors will be more important than others. The purpose of this study was to make an aesthetic factor rank list to determine the relative contributions to overall breast aesthetics. Method: Volunteers were scanned using the 3-dimensional Vectra system. Ten Scandinavian plastic surgeons rated 37 subjects, using a validated scoring system with 49 scoring items. The correlation between specific aesthetic factors and overall breast aesthetic scores of the subjects were calculated using Pearson's r, Spearman's rho, and Kendall's tau. Results: A very strong correlation was found between overall breast aesthetic score and lower pole shape (0.876, P <0.0001). This was also true for upper pole shape (0.826, P <0.0001) and breast height (0.821, P <0.0001). A strong correlation was found between overall breast aesthetic score and nipple position (0.733, P <0.0001), breast size (0.644, P <0.0001), and breast width (0.632, P <0.0001). Factors that were only moderately correlated with aesthetic score were intermammary distance (0.496, P = 0.002), nipple size and projection (0.588, P <0.0001), areolar diameter (0.484, P <0.0001), and areolar shape (0.403, P <0.0001). Perceived symmetry was a weak factor (0.363, P = 0.027). Conclusions: Aesthetic factors of the female breast can be ranked in a priority list. Shape of the lower pole and upper pole and breast height are primary factors of female breast aesthetics. These should be prioritized in any aesthetic breast surgery. Vertical dimensional factors seem to be more determinative than horizontal factors.Peer reviewe

    Effect of maternal infection on progeny growth and resistance mediated by maternal genotype and nutrient availability

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    Maternal effects of pathogen infection on progeny development and disease resistance may be adaptive and have important consequences for population dynamics. However, these effects are often context‐dependent and examples of adaptive transgenerational responses from perennials are scarce, although they may be a particularly important mechanism generating variation in the offspring of long‐lived species. Here, we studied the effect of maternal infection of Plantago lanceolata by Podosphaera plantaginis, a fungal parasite, on the growth, flower production and resistance of the progeny of six maternal genotypes in nutrient‐rich and nutrient‐poor environments. For this purpose, we combined a common garden study with automated phenotyping measurements of early life stages, and an inoculation experiment. Our results show that the effects of infection on the mother plants transcend to impact their progeny. Although maternal infection decreased total leaf and flower production of the progeny by the end of the growing season, it accelerated early growth and enhanced resistance to the pathogen P. plantaginis. We also discovered that the effects of maternal infection affected progeny development and resistance through a three way‐interaction between maternal genotype, maternal infection status and nutrient availability. Synthesis. Our results emphasize the importance of maternal effects mediated through genotypic and environmental factors in long‐living perennials and suggest that maternal infection can create a layer of phenotypic diversity in resistance. These results may have important implications for both epidemiological and evolutionary dynamics of host–parasite interactions in the wild

    Total Breast Reconstruction with Lipofilling after Traditional Mastectomy without the Use of Tissue Expanders

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    Background:Lipofilling can be used to reconstruct a breast without additional implants or autologous composite grafts. However, methods to maximize retention of the transferred fat remain under debate. Here, the authors present their experience of breast reconstruction with lipofilling without concomitant use of tissue expanders.Methods:Patients who had completed breast reconstruction with lipofilling between June of 2010 and June of 2016 were reviewed. Those with obtainable follow-up magnetic resonance imaging scans were included in this cross-sectional study. The hospital records were reviewed for details of the lipofilling operations. Magnetic resonance imaging scans were evaluated for the volume retention and quality of the transferred fat. The patients were asked to assess the appearance and sensitivity of the reconstructed breast, the recovery time, and any adverse effects at the fat donor area.Results:Thirty-eight women with 41 reconstructed breasts were included in the study. The median age at follow-up was 62 years (range, 48 to 78 years). They had undergone a median of four (range, two to six) lipofilling procedures with a median total volume 690 mL (range, 369 to 1350 mL). After a median follow-up of 2.1 years (range, 0.4 to 6.8 years), the median proportion of transferred fat retained was 58% (range, 14% to 119%), representing a reconstructed breast volume of 76% (range, 17% to 100%) of the contralateral breast. Oil cysts larger than 10 mm were detected in 7%. Most patients reported being satisfied with the reconstructed breast and experienced few side effects.Conclusions:Breast reconstruction with lipofilling can be performed with an acceptable number of procedures and no preoperative skin expansion. It extends the option of autologous breast reconstruction to women unsuited for major reconstructive procedures.CLINICAL QUESTION/LEVEL OF EVIDENCE:Therapeutic, IV.Peer reviewe
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