Epigenotypes of Latent Herpesvirus Genomes

Microbiological Research Group, National Center for Epidemiology, 1 Cellular and Viral Epigenotypes 2 Epigenetic Modifications of a-Herpesvirus 2.1 Methylation Patterns of Latent HSV-1 Genomes In Vitro and In Vivo 64 2.2 Histone Modifications Associated with Latent HSV-1 Genomes 65 3 Epigenetic Modifications Regulate the Activity of a p-Herpesvirus 4 Epigenetic Modifications of Latent y-Herpesvirus Genomes 67 4.1 Methylation Patterns of Herpesvirus Saimiri DNA In Vitro and In Vivo . . 68 4.2...

Epigenetic Modifications of aHerpesvirus Genomes

A-Herpesviruses have a relatively short reproductive cycle and their productive (lytic) replication results in destruction of the infected cells. In vitro they spread rapidly after infection in sensitive cell types. In vivo they establish latency first in sensory ganglia and in cells of the central nervous system, although equine herpesvirus 1 and equine herpesvirus 4 target the lymphoretic-ular system (Welch et al. 1992) and latent Marek's disease virus genomes are associated with lymphomas in...

Methods for Large Scale DNA Modification Analysis Microarrays

Microarrays constitute a significant advance in methylation analysis of complex disease because they may interrogate a very large number of loci in a highly parallel fashion. The principle of epigenomic microarrays is the same as in other kinds of arrays Fluorescently labelled fragments of the tested nucleic acids hybridize to the complementary DNA sequences on the microarray, and intensity of fluorescent signal at each specific spot represents the amount of a specific fragment in the tested...

Methylation Sensitive Restriction Enzyme Based Approaches

Methylation sensitive restriction enzymes were first applied to epigenetic studies at least three decades ago and for a long time were the primary tools for DNA methylation analysis until the fine mapping using the bisulphite modification approach was developed. The interest in MSREs is now resurging as these enzymes are the key tools for large-scale epigenomic profiling using mi-croarrays see Sect. 3.3 . Classical examples of methods using MSREs are MS-Southern and the restriction landmark...

Targeting and Distribution of the DCC

Previously it was thought that the characteristic distribution of the DCC along the X chromosome was achieved in a two-step, targeting and spreading fashion. In this model, the core components MSL-1 and MSL-2 are targeted to approximately 35 discrete sites, termed chromatin entry sites. These sites serve as nucleation centres on which a mature DCC assembles and then spreads in cis to associate with hundreds of sites along the rest of the X chromosome, where it mediates a twofold increase in...

References

Abkevich V, Camp NJ, Hensel CH, et al 2003 Predisposition locus for major depression at chromosome 12q22-12q23.2. Am J Hum Genet 73 1271-1281 Adorjan P, Distler J, Lipscher E, et al 2002 Tumour class prediction and discovery by microarray-based DNA methylation analysis. Nucleic Acids Res 30 e21 Akey DT, Akey JM, Zhang K, Jin L 2002 Assaying DNA methylation based on high- throughput melting curve approaches. Genomics 80 376-384 Allen ND, Norris ML, Surani MA 1990 Epigenetic control of transgene...

Classification of Epimutations

It is obvious that errors in replicating the DNA methylation pattern and or the histone pattern can affect the epigenetic state of a gene in the daughter cell. Such epimutations Holliday 1987 can lead to inappropriate activation of a gene that should be silent, or inactivation of a gene that should be active. Epimutations can also result from mutations in cis-regulatory elements or trans-acting factors. In the following, we will refer to epimutations that occur without any DNA sequence change...