title: Histone modifications induced by MDV infection at early cytolytic and latency phases.
abstract: BACKGROUND
  Marek's disease (MD) is a highly contagious, lymphomatous disease of chickens induced by a herpesvirus, Marek's disease virus (MDV) that is the cause of major annual losses to the poultry industry. MD pathogenesis involves multiple stages including an early cytolytic phase and latency, and transitions between these stages are governed by several host and environmental factors. The success of vaccination strategies has led to the increased virulence of MDV and selective breeding of naturally resistant chickens is seen as a viable alternative. While multiple gene expression studies have been performed in resistant and susceptible populations, little is known about the epigenetic effects of infection.
  
  
  RESULTS
  In this study, we investigated temporal chromatin signatures induced by MDV by analyzing early cytolytic and latent phases of infection in the bursa of Fabricius of MD-resistant and -susceptible birds. Major global variations in chromatin marks were observed at different stages of MD in the two lines. Differential H3K27me3 marks were associated with immune-related pathways, such as MAP kinase signaling, focal adhesion and neuroactive ligand receptor interaction, and suggested varying degrees of silencing in response to infection. Immune-related microRNAs, e.g. gga-miR-155 and gga-miR-10b, bore chromatin signatures, which suggested their contribution to MD-susceptibility. Finally, several members of the focal adhesion pathway, e.g. THBS4 and ITGA1, showed marked concordance between gene expression and chromatin marks indicating putative epigenetic regulation in response to MDV infection.
  
  
  CONCLUSIONS
  Our comprehensive analysis of chromatin signatures, therefore, revealed further clues about the epigenetic effects of MDV infection although further studies are necessary to elucidate the functional implications of the observed variations in histone modifications.
authors.affiliation: Department of Animal & Avian Sciences, University of Maryland, College Park, MD, 20742, USA. apratim.mitra@gmail.com.
authors.forename: Apratim
authors.initials: A
authors.lastname: Mitra
authors.affiliation: Department of Animal & Avian Sciences, University of Maryland, College Park, MD, 20742, USA. juanluo2008@gmail.com.
authors.forename: Juan
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Animal & Avian Sciences, University of Maryland, College Park, MD, 20742, USA. yh.he.cn@gmail.com.
authors.forename: Yanghua
authors.initials: Y
authors.lastname: He
authors.affiliation: Department of Animal Breeding and Genetics, College of Animal Sciences, China Agricultural University, Beijing, 100193, P.R. China. gylzhc@gmail.com.
authors.forename: Yulan
authors.initials: Y
authors.lastname: Gu
authors.affiliation: USDA, ARS, Avian Disease and Oncology Laboratory, East Lansing, MI, 48823, USA. huanmin.zhang@ars.usda.gov.
authors.forename: Huanmin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA. zhaok@nhlbi.nih.gov.
authors.forename: Keji
authors.initials: K
authors.lastname: Zhao
authors.affiliation: Systems Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA. cuik@nhlbi.nih.gov.
authors.forename: Kairong
authors.initials: K
authors.lastname: Cui
authors.affiliation: Department of Animal & Avian Sciences, University of Maryland, College Park, MD, 20742, USA. songj88@umd.edu.
authors.forename: Jiuzhou
authors.initials: J
authors.lastname: Song
mesh_terms: D000818:Animals; D002645:Chickens / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D060467:Disease Resistance / Q000235:genetics; D044127:Epigenesis, Genetic; D022001:Focal Adhesions / Q000378:metabolism; D016678:Genome; D006657:Histones / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D025922:Mardivirus / Q000472:pathogenicity*; D008380:Marek Disease / Q000473:pathology / Q000821:virology; D008745:Methylation; D035683:MicroRNAs / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D002843:Chromatin; D006657:Histones; D035683:MicroRNAs