Search results for "methylation"

ChemInform Abstract: Methylation of 2-Phenylamino-1,3,4-thiadiazole. A Structure Debated.

1987

The true identity of the 4-methyl-5-phenylimino-δ2-1,3,4-thiadiazoline (A) has been demonstrated. The reactions, previously reported in the literature to give A have been repeated and the structure of the compounds obtained has been established.

A Gene-Specific Requirement for FACT during Transcription Is Related to the Chromatin Organization of the Transcribed Region

2006

The FACT complex stimulates transcription elongation on nucleosomal templates. In vivo experiments also involve FACT in the reassembly of nucleosomes traversed by RNA polymerase II. Since several features of chromatin organization vary throughout the genome, we wondered whether FACT is equally required for all genes. We show in this study that the in vivo depletion of Spt16, one of the subunits of Saccharomyces cerevisiae FACT, strongly affects transcription of three genes, GAL1, PHO5, and Kluyveromyces lactis LAC4, which exhibit positioned nucleosomes at their transcribed regions. In contrast, showing a random nucleosome structure, YAT1 and Escherichia coli lacZ are only mildly influenced …

340 EPIGENETIC ANALYSIS OF DEVELOPMENTALLY IMPORTANT GENES IN BOVINE OOCYTES OF DIFFERENT ORIGINS

2010

A critical step in assisted reproductive technologies (ART) is the IVM of oocytes. The quality of the oocyte is crucial for successful fertilization and subsequent embryo development. Studies in bovine ART, and epidemiological studies in children from ART, reveal a degree of abnormal development thought to be primarily caused by aberrant DNA methylation patterns in imprinted and non-imprinted genes. Due to the inherent similarities in bovine and human preimplantation embryonic development, bovine oocyte and embryo development is increasingly being used as a model for human development. The goal of this project is to investigate the effects of specific IVM conditions on the DNA methylation …

Deciphering the histone code to build the genome structure

2017

Histones are punctuated with small chemical modifications that alter their interaction with DNA. One attractive hypothesis stipulates that certain combinations of these histone modifications may function, alone or together, as a part of a predictive histone code to provide ground rules for chromatin folding. We consider four features that relate histone modifications to chromatin folding: charge neutralisation, molecular specificity, robustness and evolvability. Next, we present evidence for the association among different histone modifications at various levels of chromatin organisation and show how these relationships relate to function such as transcription, replication and cell division…

<em>In vitro</em> tRNA Methylation Assay with the <em>Entamoeba histolytica</em> DNA and tRNA Methyltransferase Dnmt2 (Ehmeth…

2010

Protozoan parasites are among the most devastating infectious agents of humans responsible for a variety of diseases including amebiasis, which is one of the three most common causes of death from parasitic disease. The agent of amebiasis is the amoeba parasite Entamoeba histolytica that exists under two stages: the infective cyst found in food or water and the invasive trophozoite living in the intestine. The clinical manifestations of amebiasis range from being asymptomatic to colitis, dysentery or liver abscesses. E. histolytica is one of the rare unicellular parasite with 5-methylcytosine (5mC) in its genome. 1, 2 It contains a single DNA methyltransferase, Ehmeth, that belongs to the D…

Short-Term Effects on Gene-Expression and on DNA-Methylation at the Genome-Wide Level of the Iberian Ham Intake and Compared With Orange Intake: A Cr…

2021

OBJECTIVES: Diet regulates gene expression and methylation profiles by several mechanisms. However, studies analyzing the simultaneous effect of specific foods on gene-expression and DNA methylation at the genome-wide level are very scarce. Therefore our aims were: To study the short-term transcriptomics and epigenomcis effects at the genome-wide level of the Iberian ham intake compared with orange intake in the same subjects. METHODS: We carried out a cross-over randomized trial (registered at ISRCTN17906849) in 33 healhty volunteers (aged 18–50 years and 50% females) of European ancestry. After 12h fasting, participants were randomly allocated to eat 67.5 g of Iberian ham (100% pure iberi…

P051 DNA methylation signatures associated with pathogenesis Crohn's disease-related genes

2019

Linker histone H1 is essential for Drosophila development, the establishment of pericentric heterochromatin, and a normal polytene chromosome structu…

2009

We generated mutant alleles of Drosophila melanogaster in which expression of the linker histone H1 can be down-regulated over a wide range by RNAi. When the H1 protein level is reduced to ∼20% of the level in wild-type larvae, lethality occurs in the late larval – pupal stages of development. Here we show that H1 has an important function in gene regulation within or near heterochromatin. It is a strong dominant suppressor of position effect variegation (PEV). Similar to other suppressors of PEV, H1 is simultaneously involved in both the repression of euchromatic genes brought to the vicinity of pericentric heterochromatin and the activation of heterochromatic genes that depend on their pe…

Viral fitness determines the magnitude of transcriptomic and epigenomic reprogramming of defense responses in plants

2019

SUMMARYAlthough epigenetic factors may influence the expression of defense genes in plants, their role in antiviral responses and the impact of viral adaptation and evolution in shaping these interactions are still poorly explored. We used two isolates of turnip mosaic potyvirus (TuMV) with varying degrees of adaptation to Arabidopsis thaliana to address these issues. One of the isolates was experimentally evolved in the plant and presented increased load and virulence relative to the ancestral isolate. The magnitude of the transcriptomic responses were larger for the evolved isolate and indicated a role of innate immunity systems triggered by molecular patterns and effectors in the infecti…

Roles of adenine methylation and genetic mutations in adaptation to different temperatures in Serratia marcescens

2019

AbstractEpigenetic modifications can contribute to adaptation, but the relative contributions of genetic and epigenetic variation are unknown. Previous studies on the role of epigenetic changes in adaptation in eukaryotes have nearly exclusively focused on cytosine methylation (m5C), while prokaryotes exhibit a richer system of methyltransferases targetting adenines (m6A) or cytosines (m4C, m5C). DNA methylation in prokaryotes has many roles, but its potential role in adaptation still needs further investigation. We collected phenotypic, genetic, and epigenetic data using single molecule real-time sequencing of clones of the bacterium Serratia marcescens that had undergone experimental evol…