Additive genetic effects in interacting species jointly determine the outcome of caterpillar herbivory.

Plant-insect interactions are common and important in basic and applied biology. Trait and genetic variation can affect the outcome and evolution of these interactions, but the relative contributions of plant and insect genetic variation and how these interact remain unclear and are rarely subject to assessment in the same experimental context. Here, we address this knowledge gap using a recent host-range expansion onto alfalfa by the Melissa blue butterfly. Common garden rearing experiments and genomic data show that caterpillar performance depends on plant and insect genetic variation, with insect genetics contributing to performance earlier in development and plant genetics later. Our models of performance based on caterpillar genetics retained predictive power when applied to a second common garden. Much of the plant genetic effect could be explained by heritable variation in plant phytochemicals, especially saponins, peptides, and phosphatidyl cholines, providing a possible mechanistic understanding of variation in the species interaction. We find evidence of polygenic, mostly additive effects within and between species, with consistent effects of plant genotype on growth and development across multiple butterfly species. Our results inform theories of plant-insect coevolution and the evolution of diet breadth in herbivorous insects and other host-specific parasites.

The gut microbiome reflects ancestry despite dietary shifts across a hybrid zone.

The microbiome is critical to an organism's phenotype, and its composition is shaped by, and a driver of, eco-evolutionary interactions. We investigated how host ancestry, habitat and diet shape gut microbial composition in a mammalian hybrid zone between Neotoma lepida and N. bryanti that occurs across an ecotone between distinct vegetation communities. We found that habitat is the primary determinant of diet, while host genotype is the primary determinant of the gut microbiome-a finding further supported by intermediate microbiome composition in first-generation hybrids. Despite these distinct primary drivers, microbial richness was correlated with diet richness, and individuals that maintained higher dietary richness had greater gut microbial community stability. Both relationships were stronger in the relative dietary generalist of the two parental species. Our findings show that host ancestry interacts with dietary habits to shape the microbiome, ultimately resulting in the phenotypic plasticity that host-microbial interactions allow.

VWF maturation and release are controlled by 2 regulators of Weibel-Palade body biogenesis: exocyst and BLOC-2.

von Willebrand factor (VWF) is an essential hemostatic protein that is synthesized in endothelial cells and stored in Weibel-Palade bodies (WPBs). Understanding the mechanisms underlying WPB biogenesis and exocytosis could enable therapeutic modulation of endogenous VWF, yet optimal targets for modulating VWF release have not been established. Because biogenesis of lysosomal related organelle-2 (BLOC-2) functions in the biogenesis of platelet dense granules and melanosomes, which like WPBs are lysosome-related organelles, we hypothesized that BLOC-2-dependent endolysosomal trafficking is essential for WPB biogenesis and sought to identify BLOC-2-interacting proteins. Depletion of BLOC-2 caused misdirection of cargo-carrying transport tubules from endosomes, resulting in immature WPBs that lack endosomal input. Immunoprecipitation of BLOC-2 identified the exocyst complex as a binding partner. Depletion of the exocyst complex phenocopied BLOC-2 depletion, resulting in immature WPBs. Furthermore, releasates of immature WPBs from either BLOC-2 or exocyst-depleted endothelial cells lacked high-molecular weight (HMW) forms of VWF, demonstrating the importance of BLOC-2/exocyst-mediated endosomal input during VWF maturation. However, BLOC-2 and exocyst showed very different effects on VWF release. Although BLOC-2 depletion impaired exocytosis, exocyst depletion augmented WPB exocytosis, indicating that it acts as a clamp. Exposure of endothelial cells to a small molecule inhibitor of exocyst, Endosidin2, reversibly augmented secretion of mature WPBs containing HMW forms of VWF. These studies show that, although BLOC-2 and exocyst cooperate in WPB formation, only exocyst serves to clamp WPB release. Exocyst function in VWF maturation and release are separable, a feature that can be exploited to enhance VWF release.

The diversity and distribution of endophytes across biomes, plant phylogeny and host tissues: how far have we come and where do we go from here?

The interiors of plants are colonized by diverse microorganisms that are referred to as endophytes. Endophytes have received much attention over the past few decades, yet many questions remain unanswered regarding patterns in their biodiversity at local to global scales. To characterize research effort to date, we synthesized results from ~600 published studies. Our survey revealed a global research interest and highlighted several gaps in knowledge. For instance, of the 17 biomes encompassed by our survey, 7 were understudied and together composed only 7% of the studies that we considered. We found that fungal endophyte diversity has been characterized in at least one host from 30% of embryophyte families, while bacterial endophytes have been surveyed in hosts from only 10.5% of families. We complimented our survey with a vote counting procedure to determine endophyte richness patterns among plant tissue types. We found that variation in endophyte assemblages in above-ground tissues varied with host growth habit. Stems were the richest tissue in woody plants, whereas roots were the richest tissue in graminoids. For forbs, we found no consistent differences in relative tissue richness among studies. We propose future directions to fill the gaps in knowledge we uncovered and inspire further research.

Extreme heterogeneity of population response to climatic variation and the limits of prediction.

Certain general facets of biotic response to climate change, such as shifts in phenology and geographic distribution, are well characterized; however, it is not clear whether the observed similarity of responses across taxa will extend to variation in other population-level processes. We examined population response to climatic variation using long-term incidence data (collected over 42 years) encompassing 149 butterfly species and considerable habitat diversity (10 sites along an elevational gradient from sea level to over 2,700 m in California). Population responses were characterized by extreme heterogeneity that was not attributable to differences in species composition among sites. These results indicate that habitat heterogeneity might be a buffer against climate change and highlight important questions about mechanisms maintaining interpopulation differences in responses to weather. Despite overall heterogeneity of response, population dynamics were accurately predicted by our model for many species at each site. However, the overall correlation between observed and predicted incidence in a cross validation analysis was moderate (Pearson's r = 0.23, SE 0.01), and 97% of observed data fell within the predicted 95% credible intervals. Prediction was most successful for more abundant species as well as for sites with lower annual turnover. Population-level heterogeneity in response to climate variation and the limits of our predictive power highlight the challenges for a future of increasing climatic variability.

Rarity does not limit genetic variation or preclude subpopulation structure in the geographically restricted desert forb Astragalus lentiginosus var. piscinensis.

PREMISE OF THE STUDY: Characteristics of rare taxa include small population sizes and limited geographical ranges. The genetic consequences of rarity are poorly understood for most taxa. A small geographical range could result in reduced opportunity for isolation by distance or environment, thereby limiting genetic structure and variation, but few studies explore genetic structure at small spatial scales with sufficient resolution to test this hypothesis. Moreover, few comparative genetic studies exist among infrataxa differing in rarity. Here, we compare genetic variation among varieties of Astragalus lentiginosus differing in range size. Additionally, we ask if genetic structure exists in A. lentiginosus var. piscinensis, a rare taxon consisting of several thousand individuals that persist on ~8 km2 of alkaline soil. METHODS: We compared genetic variation among 11 varieties of A. lentiginosus differing in range size using a genotyping by sequencing (GBS) approach, which generated 11,475 single nucleotide polymorphisms (SNPs). We characterized genetic structure among subpopulations of A. lentiginosus var. piscinensis using a second GBS data set of 7274 SNPs and explored associations between genetic structure and environmental variation. KEY RESULTS: We found no association between genetic variation and range size among varieties of A. lentiginosus. Additionally, despite the extremely small range of A. lentiginosus var. piscinensis, we report a well-defined genetic structure among subpopulations associated with microhabitat variation in soil composition. CONCLUSIONS: Our results suggest that fine scale genetic structure may exist within other rare Astragalus taxa and that rarity does not preclude the maintenance of genetic diversity in this genus.

Host plant-dependent effects of microbes and phytochemistry on the insect immune response.

Herbivorous insects can defend themselves against pathogens via an immune response, which is influenced by the nutritional quality and phytochemistry of the host plant. However, it is unclear how these aspects of diet interact to influence the insect immune response and what role is played by ingested foliar microbes. We examined dietary protein, phytochemistry, and the caterpillar microbiome to understand variation in immune response of the Melissa blue butterfly, Lycaeides melissa. We also asked if these factors have host plant-specific effects by measuring L. melissa immune response when reared on a recently colonized exotic host plant (Medicago sativa) as compared to the immune response on an ancestral, native host (Astragalus canadensis). L. melissa did not experience immunological benefits directly related to consumption of the novel plant M. sativa. However, we did find negative, direct effects of phytochemical diversity and negative, direct effects of diet-derived microbial diversity on constitutive immune response for caterpillars fed M. sativa, as measured by phenoloxidase activity. Foliar protein did not directly influence the immune response, but did do so indirectly by increasing weight gain. Our results highlight the important effects of host diet on caterpillar physiology and raise the possibility that foliar microbiota, despite being rapidly passed through the gut, can affect the caterpillar immune response.

Clinical predictors of antitachycardia pacing response in implantable cardioverter defibrillator patients.

BACKGROUND: Antitachycardia pacing (ATP) provides safe and painless termination of reentrant ventricular arrhythmias in patients with implantable cardioverter defibrillator (ICDs), improving their quality of life. Established predictors of ATP responsiveness are not well known; only longer ventricular tachycardia (VT) cycle length and higher ejection fraction have been found to predict ATP success. OBJECTIVE: To investigate clinical and ECG predictors of ATP response in ICD patients with monomorphic VT. METHODS: The ICD clinic database was searched for monomorphic VT events requiring ICD therapy in patients with ischemic or non-ischemic cardiomyopathy. Each patient's first ICD encounter for VT was assessed. Patient demographics, clinical characteristics, VT rate, and ATP responsiveness (always, sometimes, and never successful) were recorded. An ECG was analyzed for QRS morphology and duration. Data was assessed for predictors of ATP responsiveness. RESULTS: In 527 patients, characteristics associated with always successful ATP included ACE-I/ARB therapy and slower VT rate (never successful ATP 197 ± 28 bpm, sometimes successful ATP 190 ± 27 bpm, always successful ATP 183 ± 22 bpm, P < .0001). Secondary prevention indication, amiodarone therapy, and longer QRS duration were associated with ATP failure. After multivariate analysis, only faster VT rate and amiodarone therapy were predictive of ATP failure. CONCLUSIONS: Neither QRS morphology nor duration was predictive of ATP success. Slower VT rate was predictive of repeated ATP responsiveness. Amiodarone therapy, which is known to increase VT cycle length, interestingly was associated with ATP failure for unclear reasons. More individualized and possibly more aggressive ATP programming may be warranted in patients on amiodarone.

Host plant associated enhancement of immunity and survival in virus infected caterpillars.

Understanding the interaction between host plant chemistry, the immune response, and insect pathogens can shed light on host plant use by insect herbivores. In this study, we focused on how interactions between the insect immune response and plant secondary metabolites affect the response to a viral pathogen. Based upon prior research, we asked whether the buckeye caterpillar, Junonia coenia (Nymphalidae), which specializes on plants containing iridoid glycosides (IGs), is less able to resist the pathogenic effects of a densovirus infection when feeding on plants with high concentrations of IGs. In a fully factorial design, individuals were randomly assigned to three treatments, each of which had two levels: (1) exposed to the densovirus versus control, (2) placed on a plant species with high concentrations of IGs (Plantago lanceolata, Plantaginaceae) versus low concentrations of IGs (P. major), and (3) control versus surface sterilized to exclude surface microbes that may contribute to viral resistance. We measured phenoloxidase (PO) activity, hemocyte counts, and gut bacterial diversity (16S ribosomal RNA) during the fourth larval instar, as well as development time, pupal weight, and survival to adult. Individuals infected with the virus were immune-suppressed (as measured by PO response and hemocyte count) and developed significantly faster than virus-free individuals. Contrary to our predictions,mortality was significantly less for virus challengedindividuals reared on the high IG plant compared to the low IG plant.This suggests that plant secondary metabolites can influence survival from viral infection and may be associated with activation of PO. Removing egg microbes did not affect the immune response or survival of the larvae. In summary, these results suggest that plant secondary metabolites are important for survival against a viral pathogen. Even though the PO response was better on the high IG plant, the extent to which this result contributes to survival against the virus needs further investigation.

Vertical stratification of the foliar fungal community in the world's tallest trees.

PREMISE OF THE STUDY: The aboveground tissues of plants host numerous, ecologically important fungi, yet patterns in the spatial distribution of these fungi remain little known. Forest canopies in particular are vast reservoirs of fungal diversity, but intracrown variation in fungal communities has rarely been explored. Knowledge of how fungi are distributed throughout tree crowns will contribute to our understanding of interactions between fungi and their host trees and is a first step toward investigating drivers of community assembly for plant-associated fungi. Here we describe spatial patterns in fungal diversity within crowns of the world's tallest trees, coast redwoods (Sequoia sempervirens). METHODS: We took a culture-independent approach, using the Illumina MiSeq platform, to characterize the fungal assemblage at multiple heights within the crown across the geographical range of the coast redwood. KEY RESULTS: Within each tree surveyed, we uncovered evidence for vertical stratification in the fungal community; different portions of the tree crown harbored different assemblages of fungi. We also report between-tree variation in the fungal community within redwoods. CONCLUSIONS: Our results suggest the potential for vertical stratification of fungal communities in the crowns of other tall tree species and should prompt future study of the factors giving rise to this stratification.

Increasing neonicotinoid use and the declining butterfly fauna of lowland California.

The butterfly fauna of lowland Northern California has exhibited a marked decline in recent years that previous studies have attributed in part to altered climatic conditions and changes in land use. Here, we ask if a shift in insecticide use towards neonicotinoids is associated with butterfly declines at four sites in the region that have been monitored for four decades. A negative association between butterfly populations and increasing neonicotinoid application is detectable while controlling for land use and other factors, and appears to be more severe for smaller-bodied species. These results suggest that neonicotinoids could influence non-target insect populations occurring in proximity to application locations, and highlights the need for mechanistic work to complement long-term observational data.

Understanding a migratory species in a changing world: climatic effects and demographic declines in the western monarch revealed by four decades of intensive monitoring.

Migratory animals pose unique challenges for conservation biologists, and we have much to learn about how migratory species respond to drivers of global change. Research has cast doubt on the stability of the eastern monarch butterfly (Danaus plexippus) population in North America, but the western monarchs have not been as intensively examined. Using a Bayesian hierarchical model, sightings of western monarchs over approximately 40 years were investigated using summer flight records from ten sites along an elevational transect in Northern California. Multiple weather variables were examined, including local and regional temperature and precipitation. Population trends from the ten focal sites and a subset of western overwintering sites were compared to summer and overwintering data from the eastern migration. Records showed western overwintering grounds and western breeding grounds had negative trends over time, with declines concentrated early in the breeding season, which were potentially more severe than in the eastern population. Temporal variation in the western monarch also appears to be largely independent of (uncorrelated with) the dynamics in the east. For our focal sites, warmer temperatures had positive effects during winter and spring, and precipitation had a positive effect during spring. These climatic associations add to our understanding of biotic-abiotic interactions in a migratory butterfly, but shifting climatic conditions do not explain the overall, long-term, negative population trajectory observed in our data.

Renal Cell Carcinoma Presenting with Paraneoplastic Hallucinations and Cognitive Decline from Limbic Encephalitis.

We present a 66-year-old woman with 2 months of visual hallucinations, unintentional weight loss, and short-term memory decline, whose clinical presentation and EEG supported a diagnosis of limbic encephalitis. Subsequent evaluation for a paraneoplastic etiology revealed a renal mass, which was resected and identified as clear cell renal carcinoma. The patient's clinical condition improved after resection of the mass. When patients present with incongruous subacute neuropsychiatric symptoms, clinicians should be mindful of paraneoplastic neurological disorders, as early diagnosis and treatment of malignancy may lead to symptomatic improvement.

Species with more volatile population dynamics are differentially impacted by weather.

Climatic variation has been invoked as an explanation of population dynamics for a variety of taxa. Much work investigating the link between climatic forcings and population fluctuation uses single-taxon case studies. Here, we conduct comparative analyses of a multi-decadal dataset describing population dynamics of 50 co-occurring butterfly species at 10 sites in Northern California. Specifically, we explore the potential commonality of response to weather among species that encompass a gradient of population dynamics via a hierarchical Bayesian modelling framework. Results of this analysis demonstrate that certain weather conditions impact volatile, or irruptive, species differently as compared with relatively stable species. Notably, precipitation-related variables, including indices of the El Niño Southern Oscillation, have a more pronounced impact on the most volatile species. We hypothesize that these variables influence vegetation resource availability, and thus indirectly influence population dynamics of volatile taxa. As one of the first studies to show a common influence of weather among taxa with similar population dynamics, the results presented here suggest new lines of research in the field of biotic-abiotic interactions.

Successful Treatment of Wounds from Nonuremic Calciphylaxis with Acellular Piscine Dermis.

In this report, we present a 57-year-old man with chronic bilateral lower extremity wounds from nonuremic calciphylaxis, which were successfully reconstructed using a piscine-derived acellular dermal matrix. The acellular dermal matrix incorporated quickly, providing a wound bed that was amenable to skin grafting. We demonstrate that this is an effective off-the-shelf solution for these chronic wounds, resulting in pain reduction and complete closure of the wounds, allowing the patient to return to his previous baseline activities, and improving his quality of life.

Rhizosphere microbial community composition shifts diurnally and in response to natural variation in host clock phenotype.

Plant-associated microbial assemblages are known to shift at time scales aligned with plant phenology, as influenced by the changes in plant-derived nutrient concentrations and abiotic conditions observed over a growing season. But these same factors can change dramatically in a sub-24-hour period, and it is poorly understood how such diel cycling may influence plant-associated microbiomes. Plants respond to the change from day to night via mechanisms collectively referred to as the internal "clock," and clock phenotypes are associated with shifts in rhizosphere exudates and other changes that we hypothesize could affect rhizosphere microbes. The mustard Boechera stricta has wild populations that contain multiple clock phenotypes of either a 21- or a 24-hour cycle. We grew plants of both phenotypes (two genotypes per phenotype) in incubators that simulated natural diel cycling or that maintained constant light and temperature. Under both cycling and constant conditions, the extracted DNA concentration and the composition of rhizosphere microbial assemblages differed between time points, with daytime DNA concentrations often triple what were observed at night and microbial community composition differing by, for instance, up to 17%. While we found that plants of different genotypes were associated with variation in rhizosphere assemblages, we did not see an effect on soil conditioned by a particular host plant circadian phenotype on subsequent generations of plants. Our results suggest that rhizosphere microbiomes are dynamic at sub-24-hour periods, and those dynamics are shaped by diel cycling in host plant phenotype. IMPORTANCE We find that the rhizosphere microbiome shifts in composition and extractable DNA concentration in sub-24-hour periods as influenced by the plant host's internal clock. These results suggest that host plant clock phenotypes could be an important determinant of variation in rhizosphere microbiomes.

Preoperative Frailty Risk in Cranioplasty Patients: Risk Analysis Index Predicts Adverse Outcomes.

Cranioplasty is a common surgical procedure used to repair cranial defects, and it is associated with significant morbidity and mortality. Although frailty is a strong predictor of poor postoperative outcomes across surgical specialties, little is known about frailty's impact on cranioplasty outcomes. This study examined the association between frailty and cranioplasty by comparing the effect of the Risk Analysis Index-Administrative (RAI-A) and the Modified Frailty Index-5 (mFI-5) on cranioplasty outcomes. Methods: The National Surgical Quality Improvement Program was queried for patients undergoing cranioplasty between 2012 and 2020. Receiver operating characteristics and multivariable analyses were used to assess the relationship of postoperative outcomes and the RAI-A, mFI-5, and increasing patient age. Results: There were 2864 included study patients with a median age of 57 years (IQR, 44-67), and a higher proportion of patients were women (57.0%) and White (68.5%). The RAI-A had a more robust predictive ability for 30-day mortality (C-Statistic, 0.741; 95% confidence interval (CI), 0.678-0.804) compared with mFI-5 (C-Statistic, 0.574; 95% CI, 0.489-0.659) and increasing patient age (C-Statistic, 0.671; 95% CI, 0.610-0.732). On multivariable analyses, frailty was independently associated with mortality and other poor postoperative outcomes (P < 0.05). Conclusions: The RAI-A demonstrated superior discrimination than the mFI-5 and increasing patient age in predicting mortality. Additionally, the RAI-A showed independent associations with nonhome discharge and postoperative complications (CDII, CDIIIb, and CDIV). The high rates of operative morbidity (5.0%-36.5%) and mortality (0.4%-3.2%) after cranioplasty highlight the importance of identifying independent risk factors for poor cranioplasty outcomes.

Mitigation of Respirable Aerosol Particles from Speech and Language Therapy Exercises.

INTRODUCTION: Phonation and speech are known sources of respirable aerosol in humans. Voice assessment and treatment manipulate all the subsystems of voice production, and previous work (Saccente-Kennedy et al., 2022) has demonstrated such activities can generate >10 times more aerosol than conversational speech and 30 times more aerosol than breathing. Aspects of voice therapy may therefore be considered aerosol generating procedures and pose a greater risk of potential airborne pathogen (eg, SARS-CoV-2) transmission than typical speech. Effective mitigation measures may be required to ensure safe service delivery for therapist and patient. OBJECTIVE: To assess the effectiveness of mitigation measures in reducing detectable respirable aerosol produced by voice assessment/therapy. METHODS: We recruited 15 healthy participants (8 cis-males, 7 cis-females), 9 of whom were voice-specialist speech-language pathologists. Optical Particle Sizers (OPS) (Model 3330, TSI) were used to measure the number concentration of respirable aerosol particles (0.3 µm-10 µm) generated during a selection of voice assessment/therapy tasks, both with and without mitigation measures in place. Measurements were performed in a laminar flow operating theatre, with near-zero background aerosol concentration, allowing us to quantify the number concentration of respiratory aerosol particles produced. Mitigation measures included the wearing of Type IIR fluid resistant surgical masks, wrapping the same masks around the end of straws, and the use of heat and moisture exchange microbiological filters (HMEFs) for a water resistance therapy (WRT) task. RESULTS: All unmitigated therapy tasks produced more aerosol than unmasked breathing or speaking. Mitigation strategies reduced detectable aerosol from all tasks to a level significantly below, or no different to, that of unmasked breathing. Pooled filtration efficiencies determined that Type IIR surgical masks reduced detectable aerosol by 90%. Surgical masks wrapped around straws reduced detectable aerosol by 96%. HMEF filters were 100% effective in mitigating the aerosol from WRT, the exercise that generated more aerosol than any other task in the unmitigated condition. CONCLUSIONS: Voice therapy and assessment causes the release of significant quantities of respirable aerosol. However, simple mitigation strategies can reduce emitted aerosol concentrations to levels comparable to unmasked breathing.

Heightened sympathetic neuron activity and altered cardiomyocyte properties in spontaneously hypertensive rats during the postnatal period.

The Spontaneously Hypertensive Rat (SHR) has increased sympathetic drive to the periphery that precedes and contributes to the development of high blood pressure, making it a useful model for the study of neurogenic hypertension. Comparisons to the normotensive Wistar Kyoto (WKY) rat have demonstrated altered active and intrinsic properties of SHR sympathetic neurons shortly before the onset of hypertension. Here we examine the structural and functional plasticity of postnatal SHR and WKY sympathetic neurons cultured alone or co-cultured with cardiomyocytes under conditions of limited extrinsic signaling. SHR neurons have an increased number of structural synaptic sites compared to age-matched WKY neurons, measured by the co-localization of presynaptic vesicular acetylcholine transporter and postsynaptic shank proteins. Whole cell recordings show that SHR neurons have a higher synaptic charge than WKY neurons, demonstrating that the increase in synaptic sites is associated with increased synaptic transmission. Differences in synaptic properties are not associated with altered firing rates between postnatal WKY and SHR neurons and are not influenced by interactions with target cardiomyocytes from either strain. Both SHR and WKY neurons show tonic firing patterns in our cultures, which are depleted of non-neuronal ganglionic cells and provide limited neurotrophic signaling. This suggests that the normal mature, phasic firing of sympathetic neurons requires extrinsic signaling, with potentially differential responses in the prehypertensive SHR, which have been reported to maintain tonic firing at later developmental stages. While cardiomyocytes do not drive neuronal differences in our cultures, SHR cardiomyocytes display decreased hypertrophy compared to WKY cells and altered responses to co-cultured sympathetic neurons. These experiments suggest that altered signaling in SHR neurons and cardiomyocytes contributes to changes in the cardiac-sympathetic circuit in prehypertensive rats as early as the postnatal period.