14 research outputs found

    Expression of Multiple Resistance Genes Enhances Tolerance to Environmental Stressors in Transgenic Poplar (Populus × euramericana ‘Guariento’)

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    Commercial and non-commercial plants face a variety of environmental stressors that often cannot be controlled. In this study, transgenic hybrid poplar (Populus × euramericana ‘Guariento’) harboring five effector genes (vgb, SacB, JERF36, BtCry3A and OC-I) were subjected to drought, salinity, waterlogging and insect stressors in greenhouse or laboratory conditions. Field trials were also conducted to investigate long-term effects of transgenic trees on insects and salt tolerance in the transformants. In greenhouse studies, two transgenic lines D5-20 and D5-21 showed improved growth, as evidenced by greater height and basal diameter increments and total biomass relative to the control plants after drought or salt stress treatments. The improved tolerance to drought and salt was primarily attributed to greater instantaneous water use efficiency (WUEi) in the transgenic trees. The chlorophyll concentrations tended to be higher in the transgenic lines under drought or saline conditions. Transformed trees in drought conditions accumulated more fructan and proline and had increased Fv/Fm ratios (maximum quantum yield of photosystem II) under waterlogging stress. Insect-feeding assays in the laboratory revealed a higher total mortality rate and lower exuviation index of leaf beetle [Plagiodera versicolora (Laicharting)] larvae fed with D5-21 leaves, suggesting enhanced insect resistance in the transgenic poplar. In field trials, the dominance of targeted insects on 2-year-old D5-21 transgenic trees was substantially lower than that of the controls, indicating enhanced resistance to Coleoptera. The average height and DBH (diameter at breast height) of 2.5-year-old transgenic trees growing in naturally saline soil were 3.80% and 4.12% greater than those of the control trees, but these increases were not significant. These results suggested that multiple stress-resistance properties in important crop tree species could be simultaneously improved, although additional research is needed to fully understand the relationships between the altered phenotypes and the function of each transgene in multigene transformants

    Genetic correlations and genome-wide associations of cortical structure in general population samples of 22,824 adults

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    Cortical thickness, surface area and volumes vary with age and cognitive function, and in neurological and psychiatric diseases. Here we report heritability, genetic correlations and genome-wide associations of these cortical measures across the whole cortex, and in 34 anatomically predefined regions. Our discovery sample comprises 22,824 individuals from 20 cohorts within the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium and the UK Biobank. We identify genetic heterogeneity between cortical measures and brain regions, and 160 genome-wide significant associations pointing to wnt/β-catenin, TGF-β and sonic hedgehog pathways. There is enrichment for genes involved in anthropometric traits, hindbrain development, vascular and neurodegenerative disease and psychiatric conditions. These data are a rich resource for studies of the biological mechanisms behind cortical development and aging

    Attenuated familial adenomatous polyposis: results from an international collaborative study.

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    AIM: The study aimed to describe genetical and clinical features of attenuated familial adenomatous polyposis (AFAP) and to propose clinical criteria and guidelines for treatment and surveillance. METHOD: A questionnaire study was carried out of polyposis registries with data on patients with presumed AFAP, defined as having ≤ 100 colorectal adenomas at age ≥ 25. RESULTS: One hundred and ninety-six patients were included. The median number of adenomas was 25 (0-100) with a uniform distribution of colorectal adenomas and carcinomas (CRC). Age at CRC diagnosis was delayed by 15 years compared with classic FAP. Eighty-two patients had a colectomy and an ileorectal anastomosis and 5/82 (6%) had a secondary proctectomy. The location of the mutation in the APC gene was known in 69/171 (40%) tested patients. Only 15/29 (52%) of mutations in APC were found in parts of the gene usually associated with AFAP (the 5' end, exon 9 and 3' end). CONCLUSIONS: A subset of FAP patients with a milder phenotype does exist and treatment and surveillance had to be modified accordingly. The mutation detection rate is lower than in classic FAP and mutations in AFAP patients are located throughout the APC gene. We propose the following clinical diagnostic criteria for AFAP: a dominant mode of inheritance of colorectal adenomatosis and <100 colorectal adenomas at age 25 or older. Colonoscopy had to be preferred to sigmoidoscopy and surveillance had to be life-long. In the majority of patients, prophylactic colectomy and ileorectal anastomosis are recommended at the age of 20-25 years

    Biomechanical analysis of hyoid bone displacement in videofluoroscopy: a systematic review of intervention effects

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    This systematic review explores studies using biomechanical analysis of hyoid bone displacement in videofluoroscopy of swallowing as a spatial outcome parameter to evaluate intervention effects. Two authors independently carried out the literature search using the electronic databases Embase, PubMed, and Cochrane Library. Differences in their search findings were settled by discussion. The search was limited to publications in the English, German, French, Spanish, or Dutch language. MeSH terms were used, supplemented by free-text words to identify the most recent publications. In addition, reference lists were searched by hand. Only studies using videofluoroscopy to evaluate the biomechanical effects of swallowing interventions in dysphagic subjects were included in the review. While the body of literature on measuring hyoid bone displacement in videofluoroscopy has grown, only 12 studies met the inclusion criteria. Several of the 12 studies had methodological shortcomings. In general, the conclusions could not be compared across the studies because of their heterogeneous designs and outcome measures. Overall, several intervention effect studies reported significant results. In particular, bolus modification and swallowing maneuvers showed a greater range of hyoid bone displacement. In light of this review, further research on hyoid bone displacement as a spatial variable in well-defined patient populations using well-defined videofluoroscopic protocols to measure intervention effects is recommended
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