Submitted to: Frontiers in Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2012
Publication Date: 2/17/2012
Citation: Luo, J., Yu, Y., Chang, S., Tian, F., Zhang, H., Song, J. 2012. DNA methylation fluctuation induced by virus infection differs between MD-resistant and -susceptible chickens. Frontiers in Genetics. 3(20):1-15. Available: http://www.frontiersin.org/epigenomics/10.3389/fgene.2012.00020/full. Interpretive Summary: Marek’s disease (MD), a virus induced cancer like disease of chickens, presents a continual threat to the poultry industry worldwide since Marek’s disease viruses evolve towards more pathogenic strains and MD outbreaks keep occurring in parts of the world. This study was aimed to advance the scientific understanding of DNA methylation, a biochemical process that is important for normal development in higher organisms and causing heritable changes responding to environments including pathogens, inducible in chickens. Out of a group of genes examined, distinct differences were identified in genes between chickens that are relatively more resistant and highly susceptible to MD. These findings will help in developing strategies to improve disease resistance in chickens.
Technical Abstract: Marek’s disease (MD) is a lymphoproliferative disease induced by Marek’s disease virus (MDV). To augment vaccination, the host genetic resistance is of importance in MD control. While researchers have been largely focused on exploring the genetic differences between resistant and susceptible chickens to advance our understanding, knowledge about epigenetic influence on resistance or susceptibility to MD is even poorly understood. In this study, DNA methylation in the promoter regions of 18 candidate genes were examined using Pyrosequencing in MD-resistant (L63) and MD–susceptible (L72) lines of chickens. The majority of the genes examined were found with higher methylation level in L72 chickens than in L63 chickens. Seven of the genes, HDAC9, GH, STAT1, CIITA, FABP3, LATS2 and H2Ac, were differentially methylated between L63 and L72. In addition, MDV challenge also altered the expression level of all three methyltransferase (DNMT1, DNMT3a and DNMT3b) genes. The methyltransferase DNMT1 was up-regulated in L72 chickens whereas the DNMT3b was down-regulated in L63 chickens at 21dpi. In summary, the findings of this study showed DNA methylation heterogeneity exists between MD-resistant and MD–susceptible chickens, and MDV challenge induces differential methylation alterations. Together, it is anticipated that epigenetic factors may play an active role in modulating resistance in MD resistant chickens and also susceptibility in MD susceptible chickens.