178 research outputs found
A Glucanase Gene Cosegregates with a QTL for Crown Rust Resistance in \u3cem\u3eL. Perenne\u3c/em\u3e
An important disease in Lolium spp. is crown rust caused by the fungal pathogen Puccinia coronata. In order to study the genetic background of crown rust resistance in L. perenne, a mapping study was carried out and is discussed below. To identify genomic regions or genes involved in resistance, STS markers are extremely useful. This candidate gene approach was applied in the present study
DNA methylation editing by CRISPR-guided excision of 5-methylcytosine
Tools for active targeted DNA demethylation are required to increase our knowledge about regulation and specific functions of this important epigenetic modification. DNA demethylation in mammals involve TET-mediated oxidation of 5- methylcytosine (5-meC), which may promote its replication-dependent dilution and/or active removal through base excision repair (BER). However, it is still unclear whether oxidized derivatives of 5-meC are simply DNA demethylation intermediates or rather epigenetic marks on their own. Unlike animals, plants have evolved enzymes that directly excise 5-meC without previous modification. In this work we have fused the catalytic domain of Arabidopsis ROS1 5-meC DNA glycosylase to a CRISPRassociated null-nuclease (dCas9) and analyzed its capacity for targeted reactivation of methylation-silenced genes, in comparison to other dCas9-effectors. We found that dCas9-ROS1, but not dCas9-TET1, is able to reactivate methylation-silenced genes and induce partial demethylation in a replication-independent manner. We also found that reactivation induced by dCas9-ROS1, as well as that achieved by two different CRISPR-based chromatin effectors (dCas9-VP160 and dCas9-p300), generally decreases with methylation density. Our results suggest that plant 5-meC DNA glycosylases are a valuable addition to the CRISPR-based toolbox for epigenetic editing
Modification of the epigenome in human cancer cells by expression of a DNA demethylase from plants
Differences in tetracycline resistance determinant carriage among Shigella flexneri and Shigella sonnei are not related to different plasmid Inc-type carriage
Objectives: The aim of this study was to establish the prevalence of the most common molecular mechanisms involved in tetracycline resistance as well as their relationship with plasmid incompatibility (Inc) groups in a collection of Shigella spp. causing traveller’s diarrhoea.
Methods: Tetracycline susceptibility was established in 187 Shigella spp. (74 Shigella flexneri and 113 Shigella sonnei), of which 153 isolates were recovered as a confirmed cause of traveller’s diarrhoea. The prevalence of the tet(A), tet(B) and tet(G) genes was analysed by PCR. Eighteen plasmid Inc groups was determined in a subset of 59 isolates.
Results: Among 154 tetracycline-resistant isolates, 122 (79.2%) harboured at least tet(A) or tet(B). The tet(B) gene was the most frequently detected, being present in 70 isolates (45.5%), whilst tet(A) was detected in 57 isolates (37.0%). The tet(G) gene was present in only 11 (7.2%) isolates. Moreover, the tet(A) gene was more frequent in S. sonnei (P = 0.0007), whilst the tet(B) gene was more frequent in S. flexneri (P < 0.0001). Plasmids belonging to Inc group B (P < 0.05) were significantly more frequent among S. flexneri, whilst those belonging to groups K, FIC and FIIA (P < 0.05) were preferentially detected among S. sonnei.
Conclusion: The prevalence of the tet(A) and tet(B) genes differed between S. sonnei and S. flexneri. Moreover, the prevalence of plasmid Inc groups in S. flexneri and S. sonnei differed. However, no relationship was found between the two phenomena
Mutación infrecuente en el síndrome renal-coloboma: A propósito de un caso y revisión
El síndrome renal-coloboma es una enfermedad autosómica dominante caracterizada por hipodisplasia renal y coloboma. Se presenta el caso de una niña de 12 años afecta de enfermedad renal crónica, colobomas papilares bilaterales y mutación excepcional del gen PAX-2 . Con diagnóstico prenatal de hipoplasia renal bilateral, a los 5 días de vida, presentó clínica y datos analíticos compatibles con enfermedad renal crónica. En los controles posteriores, se apreció reflujo vesicoureteral grado ii bilateral, que se resolvió espontáneamente, proteinuria mantenida en rango no nefrótico controlada con enalapril y colobomas bilaterales con atrofia macular izquierda. La función renal se mantuvo estable. El estudio genético demostró mutación p.R104X de novo sin sentido en heterocigosis. Globalmente, existen documentados 80 casos de síndrome renal- coloboma asociado a mutaciones de este gen. Las evaluaciones oftalmológicas y genéticas son fundamentales en los casos de hipodisplasia renal. La función renal determinará el pronóstico. Se realizó una revisión bibliográfica de la etiopatogenia de la enfermedad. Renal-coloboma syndrome is an autosomal dominant disease characterized by renal hypodysplasia and coloboma. A case of a 12-year-old girl with chronic kidney disease, bilateral optic nerve colobomas and an exceptional PAX-2 gene mutation is presented. Diagnosed in prenatal scans with bilateral renal hypoplasia, she presented clinical and laboratory findings of chronic kidney disease at 5 days of life. Following tests Mutación infrecuente en el síndrome renal-coloboma: A propósito de un caso y revisión Infrequent mutation in renal-coloboma syndrome: Case report and review showed grade II bilateral vesicoureteral reflux spontaneously solved, maintained non nephrotic proteinuria controlled with enalapril and bilateral colobomas with left macular atrophy. Renal function remained stable. Genetic study showed de novo and non sense mutation p.R104X in heterocygosis. Currently there are 80 published cases of renal-coloboma syndrome associated with this gene mutations. Ophthalmologic and genetic evaluations are crucial in cases affected by renal hypodysplasia. Renal function will establish prognosis. We review the etiopathogenesis of this disease
El plomo escrito del Tos Pelat (Moncada, Valencia)
The aim of this paper is to edit a new Iberian lead inscription found in Tos Pelat (Moncada, valencia). In spite of this fragmentary condition, its text is possibly signary with a sacred or votive function
Exploration of cannabis use and polygenic risk scores on the psychotic symptom progression of a FEP cohort
Cannabis use is highly prevalent in first-episode psychosis (FEP) and plays a critical role in its onset and prognosis, but the genetic underpinnings promoting both conditions are poorly understood. Current treatment strategies for cannabis cessation in FEP are clearly inefficacious. Here, we aimed to characterize the association between cannabis-related polygenic risk scores (PRS) on cannabis use and clinical course after a FEP. A cohort of 249 FEP individuals were evaluated during 12 months. Symptom severity was measured with the Positive and Negative Severity Scale and cannabis use with the EuropASI scale. Individual PRS for lifetime cannabis initiation (PRSCI) and cannabis use disorder (PRSCUD) were constructed. Current cannabis use was associated with increased positive symptoms. Cannabis initiation at younger ages conditioned the 12-month symptom progression. FEP patients with higher cannabis PRSCUD reported increased baseline cannabis use. PRSCI was associated with the course of negative and general symptomatology over follow-up. Cannabis use and symptom progression after a FEP were modulated by cannabis PRS, suggesting that lifetime initiation and use disorders may have partially independent genetic factors. These exploratory results may be the first step to identify those FEP patients more vulnerable to cannabis use and worse outcomes to ultimately develop tailored treatments
One-step nucleic acid amplification (Osna) of sentinel lymph node in early-stage endometrial cancer: Spanish multicenter study (endo-osna)
The objective of this study was to evaluate the efficacy of one-step nucleic acid amplification (OSNA) for the detection of sentinel lymph node (SLN) metastasis compared to standard pathological ultrastaging in patients with early-stage endometrial cancer (EC). A total of 526 SLNs from 191 patients with EC were included in the study, and 379 SLNs (147 patients) were evaluated by both methods, OSNA and standard pathological ultrastaging. The central 1 mm portion of each lymph node was subjected to semi-serial sectioning at 200 µm intervals and examined by hematoxylin–eosin and immunohistochemistry with CK19; the remaining tissue was analyzed by OSNA for CK19 mRNA. The OSNA assay detected metastases in 19.7% of patients (14.9% micrometastasis and 4.8% macrometastasis), whereas pathological ultrastaging detected metastasis in 8.8% of patients (3.4% micrometastasis and 5.4% macrometastasis). Using the established cut-off value for detecting SLN metastasis by OSNA in EC (250 copies/µL), the sensitivity of the OSNA assay was 92%, specificity was 82%, diagnostic accuracy was 83%, and the negative predictive value was 99%. Discordant results between both methods were recorded in 20 patients (13.6%). OSNA resulted in an upstaging in 12 patients (8.2%). OSNA could aid in the identification of patients requiring adjuvant treatment at the time of diagnosis. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Pathological Features in Paediatric Patients with TK2 Deficiency
Thymidine kinase (TK2) deficiency causes mitochondrial DNA depletion syndrome. We aimed to report the clinical, biochemical, genetic, histopathological, and ultrastructural features of a cohort of paediatric patients with TK2 deficiency. Mitochondrial DNA was isolated from muscle biopsies to assess depletions and deletions. The TK2 genes were sequenced using Sanger sequencing from genomic DNA. All muscle biopsies presented ragged red fibres (RRFs), and the prevalence was greater in younger ages, along with an increase in succinate dehydrogenase (SDH) activity and cytochrome c oxidase (COX)-negative fibres. An endomysial inflammatory infiltrate was observed in younger patients and was accompanied by an overexpression of major histocompatibility complex type I (MHC I). The immunofluorescence study for complex I and IV showed a greater number of fibres than those that were visualized by COX staining. In the ultrastructural analysis, we found three major types of mitochondrial alterations, consisting of concentrically arranged lamellar cristae, electrodense granules, and intramitochondrial vacuoles. The pathological features in the muscle showed substantial differences in the youngest patients when compared with those that had a later onset of the disease. Additional ultrastructural features are described in the muscle biopsy, such as sarcomeric de-structuration in the youngest patients with a more severe phenotype
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