Conservation Genetics of North Island Kōkako (Callaeas wilsoni)

Conservation genetics has recently been recognised as an important, although often overlooked, aspect of wildlife management. Applying molecular techniques and genetic concepts to management strategies has the potential to significantly improve current and future recovery efforts. Wildlife translocations are often used for threatened species management in New Zealand, in which the selection of appropriate source populations is an important decision. North Island kōkako (Callaeas wilsoni) are an endemic, threatened songbird distributed across 24 relict and translocated populations in the North Island of New Zealand. Translocations have significantly influenced kōkako recovery. As such, kōkako are one of the most commonly translocated species in New Zealand. Integrating genetic techniques and recommendations into source population selection will help ensure the long-term success of future translocation projects. Te Hauturu-o-Toi is currently the largest population of kōkako but is thought to have been established by a founding population of as few as nine individuals. The aim of this research was to assess the suitability of the Hauturu kōkako population as a future source for translocations using molecular methods. In particular, the aim was to address two aspects of a source population that contribute to the overall success of a translocation; genetic diversity and disease status. To do so, the level of genetic variation across six populations and the presence of Psittacine Beak and Feather Disease on Hauturu was examined. Such research provides conservation managers with important genetic information that can be applied to best protect kōkako in future. Conserving genetic diversity is important for long-term survival of endangered species. As translocations involve a small number of individuals and create a genetic bottleneck, sourcing founder birds from genetically diverse populations helps ensure long-term translocation success. I developed 21 kōkako-specific microsatellite primers using a whole kōkako genome, that were then multiplexed to infer genetic diversity and population structure in one translocated (Hauturu) and five relict (Mapara, Mangatutu, Te Urewera, Waipapa and Bay of Plenty) kōkako populations. A similar level of genetic diversity was apparent across all populations, providing evidence to support the use of Hauturu as a source for future translocations. Both multivariate and Bayesian methods recognised a clear population structure (K=3), identifying kōkako from Hauturu and Mapara as genetically distinct from the other four sites. Understanding the differentiation between kōkako populations will allow managers to plan translocations that maximise genetic diversity and hence translocation success. Disease risk and spread has the potential to induce a translocation failure. A kōkako on Hauturu developed aberrant coloured plumage and features (claws, legs, beak) between sampling seasons (2013–2015), reminiscent of Psittacine Beak and Feather Disease (PBFD). PBFD typically infects psittacine species, but due to high recombination rates can host-switch for infection in non-psittacine species. The Hauturu population was screened for PBFD using polymerase chain reaction, with all individuals (n=31) testing negative. There is no evidence for a host switching event from red-crowned parakeets (Cyanoramphus novaezelandiae) on Hauturu into kōkako, therefore, a translocation from Hauturu is unlikely to facilitate PBFD spread. Following this result, the melanocortin-1 receptor (MC1R) gene was amplified as an alternative explanation, looking for sequence variants between the before (normal), after (aberrant) and seven normal kōkako (also from Hauturu). The MC1R gene was selected as it has a pleiotropic role in regulating both melanin deposition and physiological stress responses. No mutational differences were found, and it is recommended that future research includes screening of alternative candidate genes or explores epigenetic mechanisms to provide an explanation for the observed phenotype

Interleukin-1 signaling in the basolateral amygdala is necessary for heroin-conditioned immunosuppression

Heroin administration suppresses the production of inducible nitric oxide (NO), as indicated by changes in splenic inducible nitric oxide synthase (iNOS) and plasma nitrate/nitrite. Since NO is a measure of host defense against infection and disease, this provides evidence that heroin can increase susceptibility to pathogens by directly interacting with the immune system. Previous research in our laboratory has demonstrated that these immunosuppressive effects of heroin can also be conditioned to environmental stimuli by repeatedly pairing heroin administration with a unique environmental context. Re-exposure to a previously drug-paired context elicits immunosuppressive effects similar to heroin administration alone. In addition, our laboratory has reported that the basolateral amygdala (BLA) and medial nucleus accumbens shell (mNAcS) are critical neural substrates that mediate this conditioned effect. However, our understanding of the contributing mechanisms within these brain regions is limited. It is known that the cytokine interleukin-1 (IL-1) plays an important role in learning and memory. In fact, our laboratory has demonstrated that inhibition of IL-1β expression in the dorsal hippocampus (DH) prior to reexposure to a heroin-paired context prevents the suppression of measures of NO production. Therefore, the present studies sought to further investigate the role of IL-1 in heroin-conditioned immunosuppression. Blockade of IL-1 signaling in the BLA, but not in the caudate putamen or mNAcS, using IL-1 receptor antagonist (IL-1Ra) attenuated heroin-conditioned immunosuppression of NO production as measured by plasma nitrate/nitrite and iNOS mRNA expression in spleen tissue. Taken together, these findings suggest that IL-1 signaling in the BLA is necessary for the expression of heroin-conditioned immunosuppression of NO production and may be a target for interventions that normalize immune function in heroin users and patient populations exposed to opiate regimens

Risk of mortality (including sudden cardiac death) and major cardiovascular events in atypical and typical antipsychotic users: a study with the general practice research database.

Objective. Antipsychotics have been associated with increased cardiac events including mortality. This study assessed cardiac events including mortality among antipsychotic users relative to nonusers. Methods. The General Practice Research Database (GPRD) was used to identify antipsychotic users, matched general population controls, and psychiatric diseased nonusers. Outcomes included cardiac mortality, sudden cardiac death (SCD), all-cause mortality (excluding suicide), coronary heart disease (CHD), and ventricular arrhythmias (VA). Sensitivity analyses were conducted for age, dose, duration, antipsychotic type, and psychiatric disease. Results. 183,392 antipsychotic users (115,491 typical and 67,901 atypical), 544,726 general population controls, and 193,920 psychiatric nonusers were identified. Nonusers with schizophrenia, dementia, or bipolar disorder had increased risks of all-cause mortality compared to general population controls, while nonusers with major depression had comparable risks. Relative to psychiatric nonusers, the adjusted relative ratios (aRR) of all-cause mortality in antipsychotic users was 1.75 (95% CI: 1.64-1.87); cardiac mortality 1.72 (95% CI: 1.42-2.07); SCD primary definition 5.76 (95% CI: 2.90-11.45); SCD secondary definition 2.15 (95% CI: 1.64-2.81); CHD 1.16 (95% CI: 0.94-1.44); and VA 1.16 (95% CI: 1.02-1.31). aRRs of the various outcomes were lower for atypical versus typical antipsychotics (all-cause mortality 0.83 (95% CI: 0.80-0.85); cardiac mortality 0.89 (95% CI: 0.82-0.97); and SCD secondary definition 0.76 (95% CI: 0.55-1.04). Conclusions. Antipsychotic users had an increased risk of cardiac mortality, all-cause mortality, and SCD compared to a psychiatric nonuser cohort

The Role of Brain Interleukin-1 in Stress-Enhanced Fear Learning

Posttraumatic stress disorder (PTSD) has been shown to be associated with pro-inflammatory markers, including elevated plasma levels of interleukin-1β (IL-1β). However, the precise role of neuroinflammation and central immune signaling on the development of this debilitating psychological disorder is not known. Here, we used stress-enhanced fear learning (SEFL), an animal model of the disorder, to examine the role of central IL-1β in PTSD. The results show that the severe stressor in SEFL induces a time-dependent increase in IL-1β immunoreactivity and mRNA expression within the dentate gyrus of the dorsal hippocampus (DH). There was no increase in IL-1β in the basolateral amygdala or the perirhinal cortex. Moreover, blocking the action of IL-1β following the severe stressor with IL-1 receptor antagonist (10 μg, intracerebroventricular (i.c.v.), 24 and 48 h after the stressor) prevented the development of SEFL. To provide further support for the role of IL-1β in the development of SEFL, we show that systemic morphine, a treatment which is known to reduce both PTSD and SEFL, also reduces IL-1β expression in the DH induced by the severe stressor. These studies provide the first evidence that IL-1 is involved SEFL and suggest that IL-1 signaling in the brain may have a critical role in the development of PTSD

Root microbiota drive direct integration of phosphate stress and immunity

Plants live in biogeochemically diverse soils that harbor extraordinarily diverse microbiota. Plant organs associate intimately with a subset of these microbes; this community’s structure can be altered by soil nutrient content. Plant-associated microbes can compete with the plant and with each other for nutrients; they can also provide traits that increase plant productivity. It is unknown how the plant immune system coordinates microbial recognition with nutritional cues during microbiome assembly. We establish that a genetic network controlling phosphate stress response influences root microbiome community structure, even under non-stress phosphate conditions. We define a molecular mechanism regulating coordination between nutrition and defense in the presence of a synthetic bacterial community. We demonstrate that the master transcriptional regulators of phosphate stress response in Arabidopsis also directly repress defense, consistent with plant prioritization of nutritional stress over defense. Our work will impact efforts to define and deploy useful microbes to enhance plant performance

Design of synthetic bacterial communities for predictable plant phenotypes

Specific members of complex microbiota can influence host phenotypes, depending on both the abiotic environment and the presence of other microorganisms. Therefore, it is challenging to define bacterial combinations that have predictable host phenotypic outputs. We demonstrate that plant-bacterium binary-association assays inform the design of small synthetic communities with predictable phenotypes in the host. Specifically, we constructed synthetic communities that modified phosphate accumulation in the shoot and induced phosphate starvation-responsive genes in a predictable fashion. We found that bacterial colonization of the plant is not a predictor of the plant phenotypes we analyzed. Finally, we demonstrated that characterizing a subset of all possible bacterial synthetic communities is sufficient to predict the outcome of untested bacterial consortia. Our results demonstrate that it is possible to infer causal relationships between microbiota membership and host phenotypes and to use these inferences to rationally design novel communitie

Design and Analysis of Rhesus Cytomegalovirus IL-10 Mutants as a Model for Novel Vaccines against Human Cytomegalovirus

Human cytomegalovirus (HCMV) expresses a viral ortholog (CMVIL-10) of human cellular interleukin-10 (cIL-10). Despite only ∼26% amino acid sequence identity, CMVIL-10 exhibits comparable immunosuppressive activity with cIL-10, attenuates HCMV antiviral immune responses, and contributes to lifelong persistence within infected hosts. The low sequence identity between CMVIL-10 and cIL-10 suggests vaccination with CMVIL-10 may generate antibodies that specifically neutralize CMVIL-10 biological activity, but not the cellular cytokine, cIL-10. However, immunization with functional CMVIL-10 might be detrimental to the host because of its immunosuppressive properties.Structural biology was used to engineer biologically inactive mutants of CMVIL-10 that would, upon vaccination, elicit a potent immune response to the wild-type viral cytokine. To test the designed proteins, the mutations were incorporated into the rhesus cytomegalovirus (RhCMV) ortholog of CMVIL-10 (RhCMVIL-10) and used to vaccinate RhCMV-infected rhesus macaques. Immunization with the inactive RhCMVIL-10 mutants stimulated antibodies against wild-type RhCMVIL-10 that neutralized its biological activity, but did not cross-react with rhesus cellular IL-10.This study demonstrates an immunization strategy to neutralize RhCMVIL-10 biological activity using non-functional RhCMVIL-10 antigens. The results provide the methodology for targeting CMVIL-10 in vaccine, and therapeutic strategies, to nullify HCMV's ability to (1) skew innate and adaptive immunity, (2) disseminate from the site of primary mucosal infection, and (3) establish a lifelong persistent infection

Influence of Socioeconomic Status Trajectories on Innate Immune Responsiveness in Children

Lower socioeconomic status (SES) is consistently associated with poor health, yet little is known about the biological mechanisms underlying this inequality. In children, we examined the impact of early-life SES trajectories on the intensity of global innate immune activation, recognizing that excessive activation can be a precursor to inflammation and chronic disease.Stimulated interleukin-6 production, a measure of immune responsiveness, was analyzed ex vivo for 267 Canadian schoolchildren from a 1995 birth cohort in Manitoba, Canada. Childhood SES trajectories were determined from parent-reported housing data using a longitudinal latent-class modeling technique. Multivariate regression was conducted with adjustment for potential confounders.SES was inversely associated with innate immune responsiveness (p=0.003), with persistently low-SES children exhibiting responses more than twice as intense as their high-SES counterparts. Despite initially lower SES, responses from children experiencing increasing SES trajectories throughout childhood were indistinguishable from high-SES children. Low-SES effects were strongest among overweight children (p<0.01). Independent of SES trajectories, immune responsiveness was increased in First Nations children (p<0.05) and urban children with atopic asthma (p<0.01).These results implicate differential immune activation in the association between SES and clinical outcomes, and broadly imply that SES interventions during childhood could limit or reverse the damaging biological effects of exposure to poverty during the preschool years