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101.
Susanna Peters Jafargholi Imani Vera Mahler Kay Foetisch Susanne Kaul Kathrin E. Paulus Stephan Scheurer Stefan Vieths Karl-Heinz Kogel 《Transgenic research》2011,20(3):547-556
Pathogenesis-related protein-10 (PR10) is a ubiquitous small plant protein induced by microbial pathogens and abiotic stress
that adversely contributes to the allergenic potency of many fruits and vegetables, including carrot. In this plant, two highly
similar genes encoding PR10 isoforms have been isolated and designated as allergen Dau c 1.01 and Dau c 1.02. The aim of the
study was to generate PR10-reduced hypoallergenic carrots by silencing either one of these genes in transgenic carrots by
means of RNA interference (RNAi). The efficiency of gene silencing by stably expressed hairpin RNA (hnRNA) was documented
by means of quantitative RT-PCR (qPCR) and immunoblotting. Quantification of the residual protein revealed that PR10 accumulation
was strongly decreased compared with untransformed controls. Treatment of carrot plants with the PR protein-inducing chemical
salicylic acid resulted in an increase of PR10 isoforms only in wild-type but not in Dau c 1-silenced mutants. The decrease
of the allergenic potential in Dau c 1-silenced plants was sufficient to cause a reduced allergenic reactivity in patients
with carrot allergy, as determined with skin prick tests (SPT). However, simultaneous silencing of multiple allergens will
be required to design hypoallergenic carrots for the market. Our findings demonstrate the feasibility of creating low-allergenic
food by using RNAi. This constitutes a reasonable approach to allergen avoidance. 相似文献
102.
Viral genome segmentation can result from a trade-off between genetic content and particle stability
Ojosnegros S García-Arriaza J Escarmís C Manrubia SC Perales C Arias A Mateu MG Domingo E 《PLoS genetics》2011,7(3):e1001344
The evolutionary benefit of viral genome segmentation is a classical, yet unsolved question in evolutionary biology and RNA genetics. Theoretical studies anticipated that replication of shorter RNA segments could provide a replicative advantage over standard size genomes. However, this question has remained elusive to experimentalists because of the lack of a proper viral model system. Here we present a study with a stable segmented bipartite RNA virus and its ancestor non-segmented counterpart, in an identical genomic nucleotide sequence context. Results of RNA replication, protein expression, competition experiments, and inactivation of infectious particles point to a non-replicative trait, the particle stability, as the main driver of fitness gain of segmented genomes. Accordingly, measurements of the volume occupation of the genome inside viral capsids indicate that packaging shorter genomes involves a relaxation of the packaging density that is energetically favourable. The empirical observations are used to design a computational model that predicts the existence of a critical multiplicity of infection for domination of segmented over standard types. Our experiments suggest that viral segmented genomes may have arisen as a molecular solution for the trade-off between genome length and particle stability. Genome segmentation allows maximizing the genetic content without the detrimental effect in stability derived from incresing genome length. 相似文献
103.
Corina M. Fusari Verónica V. Lia Verónica Nishinakamasu Jeremías E. Zubrzycki Andrea F. Puebla Alberto E. Maligne H. Esteban Hopp Ruth A. Heinz Norma B. Paniego 《Molecular breeding : new strategies in plant improvement》2011,28(1):73-89
Single nucleotide polymorphisms (SNPs) and insertions/deletions (indels) are increasingly used for cultivar identification,
construction of genetic maps, genetic diversity assessment, association mapping and marker-assisted breeding. Although there
are several highly sensitive methods for the detection of polymorphisms, most of them are often beyond the budget of medium-throughput
academic laboratories or seed companies. Heteroduplex analysis by enzymatic cleavage (CEL1CH) or denaturing high-performance
liquid chromatography (dHPLC) has been successfully used to examine genetic variation in several plant and animal species.
In this work, we assess and compare the performance of both methods in sunflower by genotyping SNPs from a set of 24 selected
polymorphic candidate genes. The CEL1CH method allowed us to accurately detect allele differences in 10 out of 24 regions
using an in-house prepared CEL1 enzyme (celery single strand endonuclease 1, Apium graveolens L.). Similarly, a total of 11 regions were successfully optimized for dHPLC analysis. As a scaling-up approach, both strategies
were tested to genotype either 42 SNPs/indels in 22 sunflower accessions from the local germplasm bank or 33 SNPs/indels in
90 recombinant inbred lines (RILs) for genetic mapping purposes. Summarizing, a total of 601 genotypes were efficiently analyzed
either with CEL1CH (110) or dHPCL (491). In conclusion, CEL1CH and dHPLC proved to be robust, complementary methods, allowing
medium-scale laboratories to scale up the number of both SNPs and individuals to be included in genetic studies and targeted
germplasm diversity characterization (EcoTILLING). 相似文献
104.
105.
106.
Annamaria Leccese Raffaella Viti Susanna Bartolini 《Central European Journal of Biology》2011,6(2):199-204
Two solvent extraction procedures were used to investigate the extraction efficiency in terms of total antioxidant capacity
and total phenols in apricot fruit. Samples were either sequentially extracted with aqueous ethanol (ethanol/water 80% v/v)
and tetrahydrofuran or directly extracted with tetrahydrofuran. Each extract was analyzed for total antioxidant capacity by
the Trolox Equivalent Antioxidant Capacity (TEAC) assay and total phenols by the Folin-Ciocalteu assay. The results showed
that using sequential solvent extraction, the majority (85%) of the total antioxidant capacity and total phenols was due to
hydrophilic compounds. In tetrahydrofuran direct extractions, the total antioxidant capacity and total phenols were higher
than values obtained with aqueous ethanol and the sum of results obtained from sequential extracts for either total antioxidant
capacity or total phenols was similar to the tetrahydrofuran-extract antioxidant values. A linear correlation between total
antioxidant capacity and total phenols was found and was independent of the solvent extraction method. In conclusion, the
choice of solvent is related to the antioxidant potential of fruit and depends on the food hydrophilic/lipophilic composition. 相似文献
107.
Genetic tools have greatly aided in tracing the sources and colonization history of introduced species. However, recurrent introductions and repeated shuffling of populations may have blurred some of the genetic signals left by ancient introductions. Styela plicata is a solitary ascidian distributed worldwide. Although its origin remains unclear, this species is believed to have spread worldwide by travelling on ship's hulls. The goals of this study were to infer the genetic structure and global phylogeography of S. plicata and to look for present-day and historical genetic patterns. Two genetic markers were used: a fragment of the mitochondrial gene Cytochrome Oxidase subunit I (COI) and a fragment of the nuclear gene Adenine Nucleotide Transporter/ADP-ATP Translocase (ANT). A total of 368 individuals for COI and 315 for ANT were sequenced from 17 locations worldwide. The levels of gene diversity were moderate for COI to high for ANT. The Mediterranean populations showed the least diversity and allelic richness for both markers, while the Indian, Atlantic and Pacific Oceans had the highest gene and nucleotide diversities. Network and phylogenetic analyses with COI and ANT revealed two groups of alleles separated by 15 and 4 mutational steps, respectively. The existence of different lineages suggested an ancient population split. However, the geographic distributions of these groups did not show any consistent pattern, indicating different phylogeographic histories for each gene. Genetic divergence was significant for many population-pairs irrespective of the geographic distance among them. Stochastic introduction events are reflected in the uneven distribution of COI and ANT allele frequencies and groups among many populations. Our results confirmed that S. plicata has been present in all studied oceans for a long time, and that recurrent colonization events and occasional shuffling among populations have determined the actual genetic structure of this species. 相似文献
108.
109.
Tat‐Ming Lo Hua Ling Susanna Su Jan Leong Chueh Loo Poh Matthew Wook Chang 《Molecular systems biology》2011,7(1)
Synthetic biology aims to systematically design and construct novel biological systems that address energy, environment, and health issues. Herein, we describe the development of a synthetic genetic system, which comprises quorum sensing, killing, and lysing devices, that enables Escherichia coli to sense and kill a pathogenic Pseudomonas aeruginosa strain through the production and release of pyocin. The sensing, killing, and lysing devices were characterized to elucidate their detection, antimicrobial and pyocin release functionalities, which subsequently aided in the construction of the final system and the verification of its designed behavior. We demonstrated that our engineered E. coli sensed and killed planktonic P. aeruginosa, evidenced by 99% reduction in the viable cells. Moreover, we showed that our engineered E. coli inhibited the formation of P. aeruginosa biofilm by close to 90%, leading to much sparser and thinner biofilm matrices. These results suggest that E. coli carrying our synthetic genetic system may provide a novel synthetic biology‐driven antimicrobial strategy that could potentially be applied to fighting P. aeruginosa and other infectious pathogens. 相似文献
110.
Lorenzo Pasotti Susanna Zucca Manuel Lupotto Maria Gabriella Cusella De Angelis Paolo Magni 《Journal of biological engineering》2011,5(1):1-13