Search results for "RNase"

A new method for the mapping of 5' ends of RNAs.

2008

In this article, we describe a new procedure to map 5' ends of RNAs. The procedure consists in the use of specific RNase H digestion of a hybrid formed by the RNA and a complementary DNA oligonucleotide. Northern blot hybridization of the resulting RNA fragment allows an accurate measurement of its length. Although we generally use this procedure as a control of previously performed primer extension analyses, the absence of nonspecific bands, which often occur in primer extensions on RNA templates with extended secondary structures, suggests that our method may be preferable when these difficult templates are analyzed.

Intra-allelic variation in introns of the S13-RNase allele distinguishes sweet, wild and sour cherries

2010

The cherry (Prunus avium), a self-incompatible diploid species, and the sour cherry (Prunus cerasus), a self-incompatible or self-compatible allotetraploid species derived from P. avium and Prunus fruticosa, share several S-RNase alleles, including S13. An inactive form, S13° ,i s found in some sour cherries. Two (AT) microsatellites are associated with allele S13-RNase, one in the first intron and one in the second. Their length polymorphisms were studied in 14 sweet and 17 wild cherries (both P. avium) and in 42 sour cherries. Fluorescent primers amplifying each microsatellite were designed and amplification prod- ucts sized on an automated sequencer. Variants ranged from 247 to 273 bp fo…

Molecular and physiological consequences of faulty eukaryotic ribonucleotide excision repair

2019

Abstract The duplication of the eukaryotic genome is an intricate process that has to be tightly safe‐guarded. One of the most frequently occurring errors during DNA synthesis is the mis‐insertion of a ribonucleotide instead of a deoxyribonucleotide. Ribonucleotide excision repair (RER) is initiated by RNase H2 and results in error‐free removal of such mis‐incorporated ribonucleotides. If left unrepaired, DNA‐embedded ribonucleotides result in a variety of alterations within chromosomal DNA, which ultimately lead to genome instability. Here, we review how genomic ribonucleotides lead to chromosomal aberrations and discuss how the tight regulation of RER timing may be important for preventin…

Analysis of S-allele genetic diversity in Sicilian almond germplasm comparing different molecular methods

2015

Italian almond germplasm is characterized by a wide diversity in several growing areas among which Sicily is one of the most important. Analysis with consensus and specific primers and DNA sequencing was performed to investigate S-RNase genetic diversity and to elucidate the homology rate within a genetic pool of 27 Italian accessions. Interestingly, some of the self-compatible cultivars did not show the presence of Sf allele. Amplicons from consensus and allele-specific PCR primers revealed a high level of variability. Sequencing of all the S-RNase amplicons derived from consensus primers allowed the identification of two new S-RNase alleles (S51 and S52). Surprisingly, despite the AA repl…

Isolation and Characterization of Epidermal DNA and RNA from Guinea Pig Skin

1971

DNA and RNA were isolated from mammalian epidermis in a relatively small scale procedure. The high purity and native state of the DNA isolated is reflected by its molar absorptivity E (P), its thermal hyperchromicity and its hyperchromicity upon DNase treatment and by its sedimentation profile as well as by its profile in a cesium chloride density gradient. The very low content of protein and RNA, as well as the data of DNA determination, indicate that this method permits the isolation of a highly purified product. This is further substantiated by the determination of UV absorption spectra and by analysis of the base composition.The mammalian skin DNA showed the following properties: Mol. w…

Single-cell RNA sequencing of SARS-CoV-2 cell entry factors in the preconceptional human endometrium.

2021

Abstract STUDY QUESTION Are SARS-CoV-2 canonical cell entry machinery, consisting of ACE2, TMPRSS2, NRP1 and LY6E, or alternative potential cell entry machinery, consisting of BSG, ANPEP, CD209, CLEC4G, TMPRSS4, TMPRSS11A, FURIN, CTSB, CTSL and IFITM1, expressed in the human endometrium across the menstrual cycle? SUMMARY ANSWER Analysis of cell entry factors for SARS-CoV-2 by single-cell RNA-sequencing (scRNAseq) in the preconceptional human endometrium reveals low risk of infection. WHAT IS KNOWN ALREADY Gene expression datasets from bulk endometrial tissue show no significant expression of the SARS-CoV-2 receptor ACE2 and TMPRSS2. This is in contrast to reported expression of ACE2 at the…

LEVELS OF RIBONUCLEASE H IN CELLS INFECTED WITH HERPES SIMPLEX VIRUS TYPE1

1981

5-methylcytosine modification of an Epstein–Barr virus noncoding RNA decreases its stability

2020

Many cellular noncoding RNAs contain chemically modified nucleotides that are essential for their function. The Epstein–Barr virus expresses two highly abundant noncoding RNAs called EBV-encoded RNA 1 (EBER1) and EBER2. To examine whether these viral RNAs contain modified nucleotides, we purified native EBERs from EBV-infected cells and performed mass spectrometry analysis. While EBER2 contains no modified nucleotides at stoichiometric amounts, EBER1 was found to carry 5-methylcytosine (m5C) modification. Bisulfite sequencing indicated that a single cytosine of EBER1 is methylated in ∼95% of molecules, and the RNA methyltransferase NSUN2 was identified as the EBER1-specific writer. Intrigui…

Inhalation solutions — Which ones may be mixed? Physico-chemical compatibility of drug solutions in nebulizers — Update 2013

2014

AbstractMany patients suffering from chronic respiratory diseases rely on inhalation therapy with nebulizers. About 25% of patients who need to inhale several different drugs per day save time by mixing them for simultaneous inhalation. This review presents a comprehensive overview of the available data concerning physico-chemical compatibility of commonly mixed nebulizer solutions and suspensions. Information is based on our in vitro studies and a thorough literature search.Results indicate that many nebulizer solutions/suspensions are mixable without provoking incompatibilities. However, certain excipients contained in some of the tested drug products could be identified as a reason for i…

Selective detection of mRNA forms encoding the major phenobarbital inducible cytochromes P450 and other members of the P450IIB family by the RNAse A …

1990

Abstract The identification of P450 mRNAs in a tissue poses the problem that members of the same P450 gene family share a high sequence homology. Studies based on oligomer probes rely on a probe covering only a few base pairs. In contrast in our study on the expression of the P450IIB gene family we used in vitro-generated antisense transcripts, covering several hundred base pairs, of the hypervariable and constant regions of the P450IIB1 and P450IIB2 cDNA, in the RNAse A protection assay of mRNA isolated from various tissues. RNAse A concentrations were adjusted to a level where this enzyme still yielded distinct fragments for a defined P450IIB1 antisense/P450IIB2 sense heteroduplex, which …