99 research outputs found
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Variation and Evolution of Fruit Ripening Traits in Tomato Species
As angiosperm seeds mature within their ovaries, ovary tissue tends to grow and transform itself into fruit, which aids the success of the seeds. Fruits that are fleshy provide numerous ways to aid in the protection and the dispersal of seeds. First, they keep seeds hidden, encased in hard walls, surrounded by poisons and unpalatable compounds, and second, they undergo developmental changes that facilitate seeds’ release. Tomatoes, a model fleshy fruit, have all these protective traits, and over the course of ripening they become the familiar fruit that is a staple crop around the world. The wild relatives of cultivated tomatoes, however, have substantial variation in ripening habits. I characterized several fruit traits and their change during ripening in wild tomato species to get a better understanding of the phenotypic variation that exists in fruits. Acquiring this background for the clade enables further investigation of genes behind these variable traits and inferences of how the traits have evolved. To associate fruit traits with genes and genomic regions for further analysis I grew introgression lines (ILs) stemming from introgressions of small portions of the genome of the tomato clade outgroup Solanum lycopersicoides, in the background of the cultivated tomato, S. lycopersicum. With these lines, I found regions of the genome that are associated with change of fruit firmness during ripening, providing data for further investigation of the genetics behind this trait. I also investigated the genetic basis of ripe fruit color variation by characterizing the gene CYC-B, which produces the enzyme responsible for turning red lycopene into the orange β-carotene, across the tomato clade. My results suggest that regulation of CYC-B has been key to the evolution of different fruit colors across the clade, and that the promoter region of the gene is involved in differentiating a β-carotene accumulating plant from a lycopene accumulating plant. The research performed here enhances our understanding of phenotypic and genotypic variation in an understudied angiosperm organ that can alter how plant species interact with animals around them, contributing to our knowledge of how fruit traits evolve and how they can enable plant success
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Evidence of fruit syndromes in the recently diverged wild tomato clade opens new possibilities for the study of fleshy fruit evolution
Societal Impact Statement
Fleshy fruits provide humans with many flavorful and nutritious crops. Understanding the diversity of these plants is fundamental to managing agriculture and food security in a changing world. This study surveyed fruit trait variation across species of tomato wild relatives and explored associations among color, size, shape, sugars, and acids. These wild tomato species native to South America can be interbred with the economically important cultivated tomato. Beyond its application to tomatoes, deepening our knowledge of how fruit traits evolve together is valuable to crop improvement efforts aimed at breeding more nutritious and appealing varieties of fruits. Summary Fleshy fruits display a striking diversity of traits, many of which are important for agriculture. The evolutionary drivers of this variation are not well understood, and most studies have relied on variation found in the wild. Few studies have explored this question on a fine-grained scale with a group of recently diverged species while controlling for environmental effects. We developed the tomato clade as a novel system for fruit trait evolution research by presenting the first common garden-based systematic survey of variation and phylogenetic signal in color, nutrition, and morphology traits across all 13 species of tomato wild relatives (Solanum sect. Lycopersicon). We laid the groundwork for further testing of potential evolutionary drivers by assessing patterns of clustering and correlation among disperser-relevant fruit traits as well as historical climate variables. We found evidence of two distinct clusters of associated fruit traits defined by color, sugar type, and malic acid concentration. We also observed correlations between a fruit\u27s external appearance and internal nutrient content that could function as honest signals to dispersers. Analyses of historical climate and soil variables revealed an association between red/orange/yellow fruits and high annual average temperature. Our results establish the tomato clade as a promising system for testing hypotheses on the drivers of divergence behind early-stage fleshy fruit evolution, particularly selective pressure from frugivores
Families\u27 healthcare experiences for children with inherited metabolic diseases: Protocol for a mixed methods cohort study
Introduction Children with inherited metabolic diseases (IMDs) often have complex and intensive healthcare needs and their families face challenges in receiving high-quality, family centred health services. Improvement in care requires complex interventions involving multiple components and stakeholders, customised to specific care contexts. This study aims to comprehensively understand the healthcare experiences of children with IMDs and their families across Canada. Methods and analysis A two-stage explanatory sequential mixed methods design will be used. Stage 1: quantitative data on healthcare networks and encounter experiences will be collected from 100 parent/guardians through a care map, 2 baseline questionnaires and 17 weekly diaries over 5-7 months. Care networks will be analysed using social network analysis. Relationships between demographic or clinical variables and ratings of healthcare experiences across a range of family centred care dimensions will be analysed using generalised linear regression. Other quantitative data related to family experiences and healthcare experiences will be summarised descriptively. Ongoing analysis of quantitative data and purposive, maximum variation sampling will inform sample selection for stage 2: a subset of stage 1 participants will participate in one-on-one videoconference interviews to elaborate on the quantitative data regarding care networks and healthcare experiences. Interview data will be analysed thematically. Qualitative and quantitative data will be merged during analysis to arrive at an enhanced understanding of care experiences. Quantitative and qualitative data will be combined and presented narratively using a weaving approach (jointly on a theme-by-theme basis) and visually in a side-by-side joint display. Ethics and dissemination The study protocol and procedures were approved by the Children\u27s Hospital of Eastern Ontario\u27s Research Ethics Board, the University of Ottawa Research Ethics Board and the research ethics boards of each participating study centre. Findings will be published in peer-reviewed journals and presented at scientific conferences
Methods for genetic manipulation of Burkholderia gladioli pathovar cocovenenans
<p>Abstract</p> <p>Background</p> <p><it>Burkholderia gladioli </it>pathovar <it>cocovenenans </it>(BGC) is responsible for sporadic food-poisoning outbreaks with high morbidity and mortality in Asian countries. Little is known about the regulation of virulence factor and toxin production in BGC, and studies in this bacterium have been hampered by lack of genetic tools.</p> <p>Findings</p> <p>Establishment of a comprehensive antibiotic susceptibility profile showed that BGC strain ATCC33664 is susceptible to a number of antibiotics including aminoglycosides, carbapenems, fluoroquinolones, tetracyclines and trimethoprim. In this study, we established that gentamicin, kanamycin and trimethoprim are good selection markers for use in BGC. Using a 10 min method for preparation of electrocompetent cells, the bacterium could be transformed by electroporation at high frequencies with replicative plasmids containing the pRO1600-derived origin of replication. These plasmids exhibited a copy number of > 100 in BGC. When co-conjugated with a transposase expressing helper plasmid, mini-Tn<it>7 </it>vectors inserted site- and orientation-specifically at a single <it>glmS</it>-associated insertion site in the BGC genome. Lastly, a <it>Himar1 </it>transposon was used for random transposon mutagenesis of BGC.</p> <p>Conclusions</p> <p>A series of genetic tools previously developed for other Gram-negative bacteria was adapted for use in BGC. These tools now facilitate genetic studies of this pathogen and allow establishment of toxin biosynthetic pathways and their genetic regulation.</p
Dysregulated fibronectin trafficking by Hsp90 inhibition restricts prostate cancer cell invasion
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.The molecular chaperone Hsp90 is overexpressed in prostate cancer (PCa) and is responsible for the folding, stabilization and maturation of multiple oncoproteins, which are implicated in PCa progression. Compared to first-in-class Hsp90 inhibitors such as 17-allylamino-demethoxygeldanamycin (17-AAG) that were clinically ineffective, second generation inhibitor AUY922 has greater solubility and efficacy. Here, transcriptomic and proteomic analyses of patient-derived PCa explants identified cytoskeletal organization as highly enriched with AUY922 treatment. Validation in PCa cell lines revealed that AUY922 caused marked alterations to cell morphology, and suppressed cell motility and invasion compared to vehicle or 17-AAG, concomitant with dysregulation of key extracellular matrix proteins such as fibronectin (FN1). Interestingly, while the expression of FN1 was increased by AUY922, FN1 secretion was significantly decreased. This resulted in cytosolic accumulation of FN1 protein within late endosomes, suggesting that AUY922 disrupts vesicular secretory trafficking pathways. Depletion of FN1 by siRNA knockdown markedly reduced the invasive capacity of PCa cells, phenocopying AUY922. These results highlight a novel mechanism of action for AUY922 beyond its established effects on cellular mitosis and survival and, furthermore, identifies extracellular matrix cargo delivery as a potential therapeutic target for the treatment of aggressive PCa
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context
Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts
Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas
Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN
Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images
Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images
of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL
maps are derived through computational staining using a convolutional neural network trained to
classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and
correlation with overall survival. TIL map structural patterns were grouped using standard
histopathological parameters. These patterns are enriched in particular T cell subpopulations
derived from molecular measures. TIL densities and spatial structure were differentially enriched
among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial
infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic
patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for
the TCGA image archives with insights into the tumor-immune microenvironment
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