204 research outputs found

    Field Assessment of AtCBF1 Transgenic Potato Lines (Solanum tuberosum) for Drought Tolerance

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    Abstract Drought prone areas have been increasing around the world and it is expected that these areas will continue to expand and become more severe due to climate change. Increasing the drought stress tolerance of cultivated potato (Solanum tuberosum) could aid in feeding the growing global population. The Arabidopsis CBF1 gene (AtCBF1), which has been shown to increase drought tolerance in other plants, was transformed into a cultivated potato line under the control of the stress inducible promoter COR15a. The expression of the AtCBF1 transgene was verified by RT-PCR and the transformed lines were evaluated in field trials to assess agronomic performance under sub-optimal water management. Despite expression of the AtCBF1 gene, none of the transgenic lines out-performed the control cultivar under drought-stressed conditions. Abiotic stress responsive genes from cultivated potato and wild related species may yield more promising results thus CBF1 genes from S. tuberosum and S. commersonii will be transformed into the potato cultivar Desiree and will be field tested for drought tolerance. Resumen Las áreas con riesgo de sequía se han estado incrementando alrededor del mundo y se espera que estas superficies continuarán en expansión volviéndose más severas debido al cambio climático. El aumento a la tolerancia al agobio hídrico de la papa cultivada (Solanum tuberosum) pudiera ayudar en la alimentación de la población global en crecimiento. El gen de Arabidopsis CBF1 (AtCBF1) que se ha demostrado que aumenta la tolerancia a la sequía en otras plantas, se introdujo en una línea de papa cultivada bajo el control del promotor de inducción de agobio COR15a. La expresión del transgen AtCBF1 se verificó mediante RT-PCR y se evaluaron las líneas transformadas en ensayos de campo para analizar el comportamiento agronómico bajo manejo subóptimo de agua. A pesar de la expresión del gen AtCBF1, ninguna de las líneas transgénicas superó en comportamiento a la variedad testigo bajo condiciones de agobio hídrico. Genes de respuesta de agobio abiótico de papa cultivada y de especies silvestres relacionadas pudieran rendir resultados más promisorios, de manera que los genes CBF1 de S. tuberosum y S. commersonii serán incorporados a la variedad de papa Desiree y serán probados en el campo para tolerancia a sequía

    Multidimensional unfolding: Determining the dimensionality of ranked preference data

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    A model is proposed which treats rankings given by a group of judges as representing regions in an isotonic space of dimensionality r . Three possible criteria for estimating lower bound dimensionality are discussed: mutual boundary, cardinality, and the occurrence of transposition groups. Problems associated with each criterion are mentioned.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45705/1/11336_2005_Article_BF02288932.pd

    Integration of Two Diploid Potato Linkage Maps with the Potato Genome Sequence

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    To facilitate genome-guided breeding in potato, we developed an 8303 Single Nucleotide Polymorphism (SNP) marker array using potato genome and transcriptome resources. To validate the Infinium 8303 Potato Array, we developed linkage maps from two diploid populations (DRH and D84) and compared these maps with the assembled potato genome sequence. Both populations used the doubled monoploid reference genotype DM1-3 516 R44 as the female parent but had different heterozygous diploid male parents (RH89-039-16 and 84SD22). Over 4,400 markers were mapped (1,960 in DRH and 2,454 in D84, 787 in common) resulting in map sizes of 965 (DRH) and 792 (D84) cM, covering 87% (DRH) and 88% (D84) of genome sequence length. Of the mapped markers, 33.5% were in candidate genes selected for the array, 4.5% were markers from existing genetic maps, and 61% were selected based on distribution across the genome. Markers with distorted segregation ratios occurred in blocks in both linkage maps, accounting for 4% (DRH) and 9% (D84) of mapped markers. Markers with distorted segregation ratios were unique to each population with blocks on chromosomes 9 and 12 in DRH and 3, 4, 6 and 8 in D84. Chromosome assignment of markers based on linkage mapping differed from sequence alignment with the Potato Genome Sequencing Consortium (PGSC) pseudomolecules for 1% of the mapped markers with some disconcordant markers attributable to paralogs. In total, 126 (DRH) and 226 (D84) mapped markers were not anchored to the pseudomolecules and provide new scaffold anchoring data to improve the potato genome assembly. The high degree of concordance between the linkage maps and the pseudomolecules demonstrates both the quality of the potato genome sequence and the functionality of the Infinium 8303 Potato Array. The broad genome coverage of the Infinium 8303 Potato Array compared to other marker sets will enable numerous downstream applications

    Contrasting Population Structures of Two Vectors of African Trypanosomoses in Burkina Faso: Consequences for Control

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    Tsetse flies are insects that transmit trypanosomes to humans (sleeping sickness) and animals (nagana). Controlling these vectors is a very efficient way to control these diseases. In Burkina Faso, a tsetse eradication campaign is presently targeting the northern part of the Mouhoun River Basin. To attain this objective, the approach has to be area-wide, i.e. the control effort targets an entire pest population within a circumscribed area. To assess the level of this isolation, we studied the genetic structure of Glossina palpalis gambiensis and Glossina tachinoides populations in the target area and in the adjacent river basins of the Comoé, the Niger and the Sissili River Basins. Our results suggest an absence of strong genetic isolation of the target populations. We therefore recommend establishing permanent buffer zones between the Mouhoun and the other river basin(s) to prevent reinvasion. This kind of study may be extended to other areas on other tsetse species

    Nasal and Plasma SARS-CoV-2 RNA Levels are Associated with Timing of Symptom Resolution in the ACTIV-2 Trial of Non-hospitalized Adults with COVID-19

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    Acute COVID-19 symptoms limit daily activities, but little is known about its association with SARS-CoV-2 viral burden. In this exploratory analysis of placebo recipients in the ACTIV-2/A5401 platform trial, we showed that high anterior nasal (AN) RNA levels and detectable plasma RNA were associated with delayed symptom improvement

    No Effect of Raltegravir Intensification on Viral Replication Markers in the Blood of HIV-1–Infected Patients Receiving Antiretroviral Therapy

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    Controversy continues regarding the extent of ongoing viral replication in HIV-1-infected patients on effective antiretroviral therapy (ART). Adding an additional potent agent, such as raltegravir, to effective ART in patients with low-level residual viremia may reveal whether there is ongoing HIV-1 replication

    Nasal and Plasma Severe Acute Respiratory Syndrome Coronavirus 2 RNA Levels Are Associated With Timing of Symptom Resolution in the ACTIV-2 Trial of Nonhospitalized Adults With Coronavirus Disease 2019

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    Acute Coronavirus Disease 2019 symptoms limit daily activities, but little is known about its association with severe acute respiratory syndrome coronavirus 2 viral burden. In this exploratory analysis of placebo recipients in the ACTIV-2/A5401 platform trial, we showed that high anterior nasal RNA levels and detectable plasma RNA were associated with delayed symptom improvement.Clinical Trials Registration.https://clinicaltrials.gov/ct2/show/NCT04518410
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