38 research outputs found

    Assessment of diversity and genetic structure is an essential step for effective use of grape germplasm collections

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    The economic importance of grapevine has driven significant efforts in genomics to accelerate the exploitation of Vitis resources for development of new cultivars. However, although a large number of clonally propagated accessions are maintained in grape germplasm collections worldwide, their use for crop improvement is limited by the scarcity of information on genetic diversity, population structure and proper phenotypic assessment. The identification of representative and manageable subset of accessions would facilitate access to the diversity available in large collections. The FEM grape germplasm resources (2273 accessions) were characterised using 22 common microsatellite loci and 384 single nucleotide polymorphisms (SNPs) to examine the structure of genetic diversity and to propose a core set of grape accessions representing the allelic diversity of the whole collection. Retention of the maximum genetic and phenotypic variability was tested for two genetic core collections and one larger core set established based on phenological records. These results can be combined to the definition of inter- and intraspecific levels of germplasm stratification, and make possible to design studies dissecting the genetic basis of agronomic and domestication-related trait

    Metastasis to parotid gland from non Head and Neck tumors

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    Most primary tumors spreading metastasis to the parotid gland are usually located in the head and neck region, nonetheless, rarely, parotid gland can also be the target of metastatic localization site of distant primary tumors. The purpose of this study was to describe a clinical series of metastasis to the parotid gland from distant primary tumors (non Head & Neck)

    Ethylene production affects blueberry fruit texture and storability

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    Ethylene, produced endogenously by plants and their organs, can induce a wide array of physiological responses even at very low concentrations. Nevertheless, the role of ethylene in regulating blueberry (Vaccinium spp.) ripening and storability is still unclear although an increase in ethylene production has been observed in several studies during blueberry ripening. To overcome this issue, we evaluated the endogenous ethylene production of a Vaccinium germplasm selection at different fruit ripening stages and after cold storage, considering also textural modifications. Ethylene and texture were further assessed also on a bi-parental full-sib population of 124 accessions obtained by the crossing between "Draper" and "Biloxi", two cultivars characterized by a different chilling requirement and storability performances. Our results were compared with an extensive literature research, carried out to collect all accessible information on published works related to Vaccinium ethylene production and sensitivity. Results of this study illustrate a likely role of ethylene in regulating blueberry shelf life. However, a generalisation valid for all Vaccinium species is not attainable because of the high variability in ethylene production between genotypes, which is strictly genotype-specific. These differences in ethylene production are related with blueberry fruit storage performances based on textural alterations. Specifically, blueberry accessions characterized by the highest ethylene production had a more severe texture decay during storage. Our results support the possibility of tailoring ad hoc preharvest and postharvest strategies to extend blueberry shelf life and quality according with the endogenous ethylene production level of each cultivar

    Structure of human NMN adenylyltransferase. A key nuclear enzyme for NAD homeostasis.

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    Abstract Nicotinamide mononucleotide adenylyltransferase (NMNAT), a member of the nucleotidyltransferase α/β-phosphodiesterases superfamily, catalyzes a universal step (NMN + ATP = NAD + PPi) in NAD biosynthesis. Localized within the nucleus, the activity of the human enzyme is greatly altered in tumor cells, rendering it a promising target for cancer chemotherapy. By using a combination of single isomorphous replacement and density modification techniques, the human NMNAT structure was solved by x-ray crystallography to a 2.5-A resolution, revealing a hexamer that is composed of α/β-topology subunits. The active site topology of the enzyme, analyzed through homology modeling and structural comparison with other NMNATs, yielded convincing evidence for a substrate-induced conformational change. We also observed remarkable structural conservation in the ATP-recognition motifs GXXXPX(T/H)XXH and SXTXXR, which we take to be the universal signature for NMNATs. Structural comparison of human and prokaryotic NMNATs may also lead to the rational design of highly selective antimicrobial drugs

    Functional effect of grapevine 1-deoxy-D-xylulose 5-phosphate synthase substitution K284N on Muscat flavour formation

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    Grape berries of Muscat cultivars (Vitis vinifera L.) contain high levels of monoterpenols and exhibit a distinct aroma related to this composition of volatiles. A structural gene of the plastidial methyl-erythritol-phosphate (MEP) pathway, 1-deoxy-D-xylulose 5-phosphate synthase (VvDXS), was recently suggested as a candidate gene for this trait, having been co-localized with a major quantitative trait locus for linalool, nerol, and geraniol concentrations in berries. In addition, a structured association study discovered a putative causal single nucleotide polymorphism (SNP) responsible for the substitution of a lysine with an asparagine at position 284 of the VvDXS protein, and this SNP was significantly associated with Muscat-flavoured varieties. The significance of this nucleotide difference was investigated by comparing the monoterpene profiles with the expression of VvDXS alleles throughout berry development in Moscato Bianco, a cultivar heterozygous for the SNP mutation. Although correlation was detected between the VvDXS transcript profile and the accumulation of free monoterpenol odorants, the modulation of VvDXS expression during berry development appears to be independent of nucleotide variation in the coding sequence. In order to assess how the non-synonymous mutation may enhance Muscat flavour, an in vitro characterization of enzyme isoforms was performed followed by in vivo overexpression of each VvDXS allele in tobacco. The results showed that the amino acid non-neutral substitution influences the enzyme kinetics by increasing the catalytic efficiency and also dramatically affects monoterpene levels in transgenic lines. These findings confirm a functional effect of the VvDXS gene polymorphism and may pave the way for metabolic engineering of terpenoid contents in grapevine

    Exploratory Study on Chemosensory Event-Related Potentials in Long COVID-19 and Mild Cognitive Impairment: A Common Pathway?

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    People affected by the Long COVID-19 (LC) syndrome often show clinical manifestations that are similar to those observed in patients with mild cognitive impairments (MCI), such as olfactory dysfunction (OD), brain fog, and cognitive and attentional diseases. This study aimed to investigate the chemosensory-evoked related potentials (CSERP) in LC and MCI to understand if there is a common pathway for the similarity of symptoms associated with these disorders. Eighteen LC patients (mean age 53; s.d. = 7), 12 patients diagnosed with MCI (mean age 67; s.d. = 6), and 10 healthy control subjects (mean age 66; s.d. = 5, 7) were recruited for this exploratory study. All of them performed a chemosensory event-related potentials (CSERP) task with the administration of trigeminal stimulations (e.g., the odorants cinnamaldehyde and eucalyptus). Study results highlighted that MCI and LC showed reduced N1 amplitude, particularly in the left frontoparietal network, involved in working memory and attentional deficits, and a reduction of P3 latency in LC. This study lays the foundations for evaluating aspects of LC as a process that could trigger long-term functional alterations, and CSERPs could be considered valid biomarkers for assessing the progress of OD and an indicator of other impairments (e.g., attentional and cognitive impairments), as they occur in MCI

    KESTREL and KITE: 52-Week Results From Two Phase III Pivotal Trials of Brolucizumab for Diabetic Macular Edema.

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    PURPOSE To compare the efficacy and safety of brolucizumab with aflibercept in patients with diabetic macular edema (DME). DESIGN Double-masked, 100-week, multicenter, active-controlled, randomized trials. METHODS Subjects were randomized 1:1:1 to brolucizumab 3 mg/6 mg or aflibercept 2 mg in KESTREL (n = 566) or 1:1 to brolucizumab 6 mg or aflibercept 2 mg in KITE (n = 360). Brolucizumab groups received 5 loading doses every 6 weeks (q6w) followed by 12-week (q12w) dosing, with optional adjustment to every 8 weeks (q8w) if disease activity was identified at predefined assessment visits; aflibercept groups received 5 doses every 4 weeks (q4w) followed by fixed q8w dosing. The primary endpoint was best-corrected visual acuity (BCVA) change from baseline at Week 52; secondary endpoints included the proportion of subjects maintained on q12w dosing, change in Diabetic Retinopathy Severity Scale score, and anatomical and safety outcomes. RESULTS At Week 52, brolucizumab 6 mg was noninferior (NI margin 4 letters) to aflibercept in mean change in BCVA from baseline (KESTREL: +9.2 letters vs +10.5 letters; KITE: +10.6 letters vs +9.4 letters; P < .001), more subjects achieved central subfield thickness (CSFT) <280 µm, and fewer had persisting subretinal and/or intraretinal fluid vs aflibercept, with more than half of brolucizumab 6 mg subjects maintained on q12w dosing after loading. In KITE, brolucizumab 6 mg showed superior improvements in change of CSFT from baseline over Week 40 to Week 52 vs aflibercept (P = .001). The incidence of ocular serious adverse events was 3.7% (brolucizumab 3 mg), 1.1% (brolucizumab 6 mg), and 2.1% (aflibercept) in KESTREL; and 2.2% (brolucizumab 6 mg) and 1.7% (aflibercept) in KITE. CONCLUSION Brolucizumab 6 mg showed robust visual gains and anatomical improvements with an overall favorable benefit/risk profile in patients with DME

    High-throughput 18K SNP array to assess genetic variability of the main grapevine cultivars from Sicily

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    The viticulture of Sicily, for its vocation, is one of the most important and ancient forms in Italy. Autochthonous grapevine cultivars, many of which known throughout the world, have always been cultivated in the island from many centuries. With the aim to preserve this large grapevine diversity, previous studies have already started to assess the genetic variability among the Sicilian cultivars by using morphological and microsatellite markers. In this study, simple sequence repeat (SSR) were utilized to verify the true-to-typeness of a large clone collection (101) belonging to 21 biotypes of the most 10 cultivated Sicilian cultivars. Afterwards, 42 Organization Internationale de la Vigne et du Vin (OIV) descriptors and a high-throughput single nucleotide polymorphism (SNP) genotyping array (Vitis18kSNP) were applied to assess genetic variability among cultivars and biotypes of the same cultivar. Ampelographic traits and high-throughput SNP genotyping platforms provided an accuracy estimation of genetic diversity in the Sicilian germplasm, showing the relationships among cultivars by cluster and multivariate analyses. The large SNP panel defined sub-clusters unable to discern among biotypes, previously classified by ampelographic analysis, belonging to each cultivar. These results suggested that a very large number of SNP did not cover the genome regions harboring few morphological traits. Genetic structure of the collection revealed a clear optimum number of groups for K = 3, clustering in the same group a significant portion of family-related genotypes. Parentage analysis highlighted significant relationships among Sicilian grape cultivars and Sangiovese, as already reported, but also the first evidences of the relationships between Nero d’Avola and both Inzolia and Catarratto. Finally, a small panel of highly informative markers (12 SNPs) allowed us to isolate a private profile for each Sicilian cultivar, providing a new tool for cultivar identification
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