Epigenetics: Medicine & Health Science Books @ . Epigenetics 1st Edition. by Jorg Tost (Editor). Be the first to review this item. Jorg Tost, Director, Centre National de Genotypage CEA before becoming Director of Laboratory for Epigenetics and Environment at the Centre National de . This volume discusses technologies that analyze global DNA methylation contents, various NGS based methods for genome-wide DNA methylation.
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The reason for the greater epigenetic complexity in plants is not simply their multicellular development but also their need to cope with an ever-changing environment due to their sessile lifestyle. Whether this is the direct result of the inheritance of epigenetic marks remains unclear, but the findings do rekindle interest in the area. The epigenetic modification of DNA with 5-methylcytosine is an important regulatory event involved in chromatin structure, genomic imprinting, inactivation epigenetifs the X chromosome, transcription, and retrotransposon silencing.
During epigenerics, CpG rich regions, so-called CpG islands, have been established as prominent features of promoter regions of genes. Histone Variants and Nucleosome Occupancy.
Coronado Island, California Date: Hundreds of human miRNAs have been identified in the human epigenwtics. Xist RNA is transcribed from the Xic on the future inactive X Xiattaches to Xi chromatin and accumulates over the chromosome triggering transcriptional silencing. Therefore, cell fate and identity are generally governed by gene expression patterns.
Jorg Tost’s Biography
While the DNA sequence in all cells of an organism is identical, each different cell type is largely defined by the specific sets of genes that are expressed and repressed in that particular cell type. Epigenetic changes play a key role in normal development as well as in disease.
The accumulation of molecular lesions in cells from mature organisms during the aging proccess is perhaps the fact that drives cells to transformation. Deficiencies in reprogramming of the germ line are likely to underlie environmentally-induced epigenetic transgenerational effects.
Rotterdam, The Netherlands Date: X inactivation is a multistep process epiegnetics comprises an ordered series of chromatin modifications that occur in a developmentally regulated manner.
In this chapter, current knowledge of the epigenetic systems of plants is compared to those discovered in other eukaryotes. Recent research suggests that changes in the epigenome may underpin genetic-environmental interactions. Besides its role in the regulation of genes, DNA methylation silences repetitive elements and appears to be important for the stability of the mammalian genome.
Molecular Mechanisms of Polycomb Silencing. Links between miRNAs and human diseases are increasingly apparent and aberrant expression of miRNAs may contribute to the development and progression of human cancer. This review focuses on the biology of genomic imprinting in mammals, discussed in two parts. X inactivation in mammals achieves dosage compensation of X chromosomal genes between XX females and XY males.
Also factors with a role in chromatin and nuclear structure, such as scaffold attachment factor A Saf-A or the histone variant macroH2A, are recruited to the Xi and have been implicated in the stabilization of the inactive state. This chapter also deals with the role of the above-mentioned chromatin-modifying mechanisms and DNA sequences in defining the range of nucleosome occupancy levels found throughout the eukaryotic genome.
In the last decade it has become increasingly clear that the DNA-associated histone proteins play an important, yet enigmatic, role in gene regulation within the mammalian genome. Polycomb and Trithorax group proteins have long been known as important epigenetic regulators of homeotic genes.
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Examples of various reading mechanisms are presented including the blocking of long-range promoter-enhancer interactions and the involvement of non-coding RNAs in chromatin repression. The Biology of Genomic Imprinting.
The final chapter, describes the fascinating potential transfer of epigenetic information across generations. Environmental factors can therefore have long-term consequences for genome function.
The second part addresses the mechanism involved in assuring the re-establishment of new imprints in the next generation. Xist is essential for initiation of X inactivation but the Xi is maintained independent of Xist by other epigenetic mechanisms. In differentiated cells Xist expression is not sufficient for initiating gene repression. A mechanism for counting and choice ensures that precisely one X chromosome remains active and all super numerous Xs are inactivated.
The three recognized mechanisms for modifying chromatin are ATP dependent chromatin remodeling, covalent modification of histones and incorporation of histone sequence variants. This is an exciting area of future research, with many potential biomedical applications. Recent studies have demonstrated that miRNA expression is regulated by different mechanisms including transcription factor binding, epigenetic alterations, and chromosomal abnormalities. One of the greatest strengths of this edited work is the variety of researchers contributing to the dynamics of the work’s comprehensive nature The ES cell epigenome possesses certain features that are unique to these cell types and are involved in the regulation of pluripotency.
The properties of gene regulatory networks such as feedback loops generated by the combinatorial action of TFs and miRNAs, which facilitate both sustained response and quick transition to stimulation, are beginning to be understood.
In particular, epigenetic alterations induced by chromatin modifying drugs or by genetic disruption of key DNA methyltransferases cause distinct changes in miRNA expression profiles in cancer cells. These initial studies raise important questions about the degree to which genetic and epigenetic pathways cooperate in human tumorigenesis, the identity of the specific cooperating genes and how they interact functionally to determine the differing biological and clinical course of tumors.
It will quite effectively cater to the needs of molecular biologists, molecular geneticists, cell and molecular biologists, animal, plant, and crop geneticists, synthetic biologists, biotechnologists, and researchers involved with the fields of stem cell and molecular aspects of cancer research.
Genetic and epigenetic mechanisms contribute to the development of human tumors, yet the typical analysis of tumors is focused on only one or the other mechanism.