30 research outputs found

    Metabolic Complementarity and Genomics of the Dual Bacterial Symbiosis of Sharpshooters

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    Mutualistic intracellular symbiosis between bacteria and insects is a widespread phenomenon that has contributed to the global success of insects. The symbionts, by provisioning nutrients lacking from diets, allow various insects to occupy or dominate ecological niches that might otherwise be unavailable. One such insect is the glassy-winged sharpshooter (Homalodisca coagulata), which feeds on xylem fluid, a diet exceptionally poor in organic nutrients. Phylogenetic studies based on rRNA have shown two types of bacterial symbionts to be coevolving with sharpshooters: the gamma-proteobacterium Baumannia cicadellinicola and the Bacteroidetes species Sulcia muelleri. We report here the sequencing and analysis of the 686,192–base pair genome of B. cicadellinicola and approximately 150 kilobase pairs of the small genome of S. muelleri, both isolated from H. coagulata. Our study, which to our knowledge is the first genomic analysis of an obligate symbiosis involving multiple partners, suggests striking complementarity in the biosynthetic capabilities of the two symbionts: B. cicadellinicola devotes a substantial portion of its genome to the biosynthesis of vitamins and cofactors required by animals and lacks most amino acid biosynthetic pathways, whereas S. muelleri apparently produces most or all of the essential amino acids needed by its host. This finding, along with other results of our genome analysis, suggests the existence of metabolic codependency among the two unrelated endosymbionts and their insect host. This dual symbiosis provides a model case for studying correlated genome evolution and genome reduction involving multiple organisms in an intimate, obligate mutualistic relationship. In addition, our analysis provides insight for the first time into the differences in symbionts between insects (e.g., aphids) that feed on phloem versus those like H. coagulata that feed on xylem. Finally, the genomes of these two symbionts provide potential targets for controlling plant pathogens such as Xylella fastidiosa, a major agroeconomic problem, for which H. coagulata and other sharpshooters serve as vectors of transmission

    Longitudinal Associations Between Perceived Parent-Child Relationship Quality and Depressive Symptoms in Adolescence

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    This longitudinal study examined bidirectional paths between perceived parent-adolescent relationship quality and depressive symptoms, as well as the moderating role of sex, age, and personality type. 1313 Dutch adolescents (51% girls) from two cohorts (923 12-year olds and 390 16-year olds at Wave 1) reported on their personality, depressive symptoms, and perceived relationship quality to parents in four waves. Consistent with a relationship erosion perspective, depressive symptoms negatively predicted perceived relationship quality with parents. Relationship quality to mothers predicted depressive symptoms for boys and girls, but relationship quality to fathers predicted depressive symptoms only for boys. Personality type only moderated initial associations between relationship quality with mothers and depressive symptoms, which were stronger for Overcontrollers and Undercontrollers than for Resilients. Results thus reveal a pattern of mutual influence between perceived relationship quality and depressive symptoms that is moderated by the interplay among parent and adolescent sex and adolescent personality type

    Parent-offspring similarity in personality and adolescents' problem behaviour

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    Contains fulltext : 55706.pdf (publisher's version ) (Closed access)Similarity in personality between adolescents and their parents may have considerable implications for adolescent well-being. We studied how the similarity in personality between 288 adolescents and their parents is linked to adolescent problem behaviour, and whether this link is mediated by warmth and control in the parent–child relationship and moderated by the personality type of the adolescent. Similarity in personality between adolescents and their parents was negatively related to internalizing and externalizing problem behaviour, both concurrently and over time. This relation was not mediated by the parent–child relationship. The effects were present for overcontrolled but not for resilient or undercontrolled adolescents

    Evaluation of an integrated care pathway for out-of-hospital treatment of older adults with an acute moderate-to-severe lower respiratory tract infection or pneumonia: protocol of a mixed methods study

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    Introduction Older adults with an acute moderate-to-severe lower respiratory tract infection (LRTI) or pneumonia are generally treated in hospitals causing risk of iatrogenic harm such as functional decline and delirium. These hospitalisations are often a consequence of poor collaboration between regional care partners, the lack of (acute) diagnostic and treatment possibilities in primary care, and the presence of financial barriers. We will evaluate the implementation of an integrated regional care pathway (‘The Hague RTI Care Bridge’) developed with the aim to treat and coordinate care for these patients outside the hospital.Methods and analysis This is a prospective mixed methods study. Participants will be older adults (age≥65 years) with an acute moderate-to-severe LRTI or pneumonia treated outside the hospital (care pathway group) versus those treated in the hospital (control group). In addition, patients, their informal caregivers and treating physicians will be asked about their experiences with the care pathway. The primary outcome of this study will be the feasibility of the care pathway, which is defined as the percentage of patients treated outside the hospital, according to the care pathway, whom fully complete their treatment without the need for hospitalisation within 30 days of follow-up. Secondary outcomes include the safety of the care pathway (30-day mortality and occurrence of complications (readmissions, delirium, falls) within 30 days); the satisfaction, usability and acceptance of the care pathway; the total number of days of bedridden status or hospitalisation; sleep quantity and quality; functional outcomes and quality of life.Ethics and dissemination The Medical Research Ethics Committee Leiden The Hague Delft (reference number N22.078) has confirmed that the Medical Research Involving Human Subjects Act does not apply to this study. The results will be published in international peer-reviewed journals.Trial registration number ISRCTN68786381

    Circular View of the <i>Baumannia</i> Genome

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    <p>Circles correspond to the following features, starting with the outermost circle: (1) forward strand genes, (2) reverse strand genes, (3) χ<sup>2</sup> deviation of local nucleotide composition from the genome average, (4) GC skew, (5) tRNAs (green lines), (6) rRNAs (blue lines); and (7) small RNAs (red lines). Color legend for CDSs and number of genes in each category are at the bottom. </p

    Genome-Based Phylogenetic Analysis of <i>Baumannia</i>

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    <div><p>(A) Maximum-likelihood tree of gamma-proteobacterial endosymbionts. The tree was built from concatenated alignments of 45 ribosomal proteins using the PHYML program. The bootstrap value is based upon 1,000 replications.</p> <p>(B) Gene order comparison of <i>Baumannia</i> and Blochmannia floridanus. The plot shows the locations of homologous proteins between the two genomes. </p></div

    The Distribution into Functional Role Categories of the 166 Predicted Genes Encoded in the 146,384-bp Partial Sequence of the <i>Sulcia</i> Genome

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    <p>Data are shown for all ORFs that encode proteins longer than 45 amino acids that have BLASTP matches with an E-value less than 10<sup>−3</sup> to proteins in complete genomes. Different fragments of the same gene are counted as one gene in the chart. </p
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