112 research outputs found
Catálogo sobre edad media y musicología
Sección: NoticiasEntre los catálogos informatizados de la Red de Bibliotecas del CSIC en Cataluña se puede consultar el de referencias bibliográficas sobre edad media y musicologíaN
Detection of aberrant DNA methylation in unique Prader — Willi syndrome patients and its diagnostic implications
Most patients with Prader - Willi syndrome have a deletion of 15q11 - 13 or maternal uniparental disomy for chromosome 15. The shortest region of deletion overlap is presently defined by the gene for the small nuclear ribonucleoprotein N (SNRPN). We have investigated the integrity of SNRPN as well as the methylation status of D15S63 (PW71) in two patients with apparently normal chromosomes 15 of biparental origin. SNRPN is normal in one patient and deleted in the other one. Both patients are intact at the D15S63 locus, but have an abnormal methylation pattern. These results suggest that a DNA sequence close to SNRPN determines the methylation status of D15S63 and that the methylation test does not only detect the common deletions and uniparental disomy, but other rare lesions as wel
A recurrent 14q32.2 microdeletion mediated by expanded TGG repeats
Nearly all recurrent microdeletion/duplication syndromes described to date are characterized by the presence of flanking low copy repeats that act as substrates for non-allelic homologous recombination (NAHR) leading to the loss, gain or disruption of dosage sensitive genes. We describe an identical 1.11 Mb heterozygous deletion of 14q32.2 including the DLK1/GTL2 imprinted gene cluster in two unrelated patients. In both patients, the deleted chromosome 14 was of paternal origin, and consistent with this both exhibit clinical features compatible with uniparental disomy (UPD) (14)mat. Using a high-resolution oligonucleotide array, we mapped the breakpoints of this recurrent deletion to large flanking (TGG)n tandem repeats, each approximately 500 bp in size and sharing ≥88% homology. These expanded (TGG)n motifs share features with known fragile sites and are predicted to form strong guanine quadruplex secondary structures. We suggest that this recurrent deletion is mediated either by NAHR between the TGG repeats, or alternatively results from their inherent instability and/or strong secondary structure. Our results define a recurrent microdeletion of the 14q32.2 imprinted gene cluster mediated by flanking (TGG)n repeats, identifying a novel mechanism of recurrent genomic rearrangement. Our observation that expanded repeats can act as catalysts for genomic rearrangement extends the role of triplet repeats in human disease, raising the possibility that similar repeat structures may act as substrates for pathogenic rearrangements genome-wid
Recommendations for a nomenclature system for reporting methylation aberrations in imprinted domains
The analysis of DNA methylation has become routine in the pipeline for diagnosis of imprinting disorders, with many publications reporting aberrant methylation associated with imprinted differentially methylated regions (DMRs). However, comparisons between these studies are routinely hampered by the lack of consistency in reporting sites of methylation evaluated. To avoid confusion surrounding nomenclature, special care is needed to communicate results accurately, especially between scientists and other health care professionals. Within the European Network for Human Congenital Imprinting Disorders we have discussed these issues and designed a nomenclature for naming imprinted DMRs as well as for reporting methylation values. We apply these recommendations for imprinted DMRs that are commonly assayed in clinical laboratories and show how they support standardized database submission. The recommendations are in line with existing recommendations, most importantly the Human Genome Variation Society nomenclature, and should facilitate accurate reporting and data exchange among laboratories and thereby help to avoid future confusion
Применение микробиологических методов для повышения нефтеотдачи на примере нефтяного месторождения Мухто (Сахалинская область)
Подбор и применение микробиологического метода увеличения нефтеотдачи на месторождении РН-Сахалинморнефтегаз.Актуальность этого метода заключается в том, что этот метод позволяет извлекать трудноизвлекаемые запасы нефти, которые увеличиваются с каждым годом. В этой работе выбирается наиболее эффективный микробный агент, и рассчитывается рентабельность этого нововведения для компании.Selection and application of the microbiological method of increasing oil recovery at the RN-Sakhalinmorneftegaz.The relevance of this method lies in the fact that this method allows you to extract hard-to-recover oil reserves, which increase every year. In this paper, the most effective microbial agent is selected, and the profitability of this innovation for the company is calculated
Mutations in NLRP5 are associated with reproductive wastage and multilocus imprinting disorders in humans
This is the final version. It first appeared at http://www.nature.com/ncomms/2015/150901/ncomms9086/full/ncomms9086.html.Human-imprinting disorders are congenital disorders of growth, development and metabolism, associated with disturbance of parent of origin-specific DNA methylation at imprinted loci across the genome. Some imprinting disorders have higher than expected prevalence of monozygotic twinning, of assisted reproductive technology among parents, and of disturbance of multiple imprinted loci, for which few causative trans-acting mutations have been found. Here we report mutations in NLRP5 in five mothers of individuals affected by multilocus imprinting disturbance. Maternal-effect mutations of other human NLRP genes, NLRP7 and NLRP2, cause familial biparental hydatidiform mole and multilocus imprinting disturbance, respectively. Offspring of mothers with NLRP5 mutations have heterogenous clinical and epigenetic features, but cases include a discordant monozygotic twin pair, individuals with idiopathic developmental delay and autism, and families affected by infertility and reproductive wastage. NLRP5 mutations suggest connections between maternal reproductive fitness, early zygotic development and genomic imprinting.L.E.D. and F.I.R. were supported by the Medical Research Council (MR/J000329/1). J.B.,
K.B., B.H., L.S. M.B. and T.E. were supported by Bundesministerium fu?r Bildung und
Forschung (grant number 01GM1513A and 01GM1513C) and C.T. was supported by an
Ipsen Fellowship Grant. The cohort ?Imprinting Disorders-Finding out Why? was
accrued through the support of the Newlife Foundation for Disabled Children and
through support from the Wessex NIHR clinical research network and NIHR Wellcome
Southampton clinical research facility. Funding for DNA collection and methylation
analysis of normal control samples was provided in part by the National Institutes of
Health R01 AI091905-01, R01 AI061471 and R01 HL082925. ERM thanks Action
Medical Research for support
The Human Retinoblastoma Gene Is Imprinted
Genomic imprinting is an epigenetic process leading to parent-of-origin–specific DNA methylation and gene expression. To date, ∼60 imprinted human genes are known. Based on genome-wide methylation analysis of a patient with multiple imprinting defects, we have identified a differentially methylated CpG island in intron 2 of the retinoblastoma (RB1) gene on chromosome 13. The CpG island is part of a 5′-truncated, processed pseudogene derived from the KIAA0649 gene on chromosome 9 and corresponds to two small CpG islands in the open reading frame of the ancestral gene. It is methylated on the maternal chromosome 13 and acts as a weak promoter for an alternative RB1 transcript on the paternal chromosome 13. In four other KIAA0649 pseudogene copies, which are located on chromosome 22, the two CpG islands have deteriorated and the CpG dinucleotides are fully methylated. By analysing allelic RB1 transcript levels in blood cells, as well as in hypermethylated and 5-aza-2′-deoxycytidine–treated lymphoblastoid cells, we have found that differential methylation of the CpG island skews RB1 gene expression in favor of the maternal allele. Thus, RB1 is imprinted in the same direction as CDKN1C, which operates upstream of RB1. The imprinting of two components of the same pathway indicates that there has been strong evolutionary selection for maternal inhibition of cell proliferation
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