Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 10/3/2007
Publication Date: 1/12/2008
Citation: Yu, Y., Zhang, H., Tian, F., Bacon, L.D., Song, J. 2008. Dna methylation variations of tvb in alv-resistant and -susceptible chickens [abstract]. Plant and Animal Genome Conference. p. 96.
Technical Abstract: Epigenetic variations can convey gene expression patterns critical for neoplastic disease initiation, progression or regression. DNA methylation is one of the main components of epigenetic modification. The tumor virus B (TVB) locus, which encodes the cellular receptors for subgroups B, D, and E of ALV, is linked to cell death and the mammalian tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) receptor. We are evaluating epigenetic factors in two inbred lines of chickens, line 63 and line 72, susceptible or resistant to ALV. The DNA methylation status of 3 CpG dinucleotides in the TVB promoter region was examined using Pyrosequencing methods. The TVB promoter region had different tissue-specific methylation patterns in each line. The CpG sites 2 and 3 had a hemimethylated pattern in the spleen, liver and hypothalamus (30% - 60% methylation). A hypomethylated pattern (< 30%) was detected in blood. Notably, the average methylation level of the TVB promoter region was significantly higher in line 72 than line 63 in the hypothalamus (P<0.0001), blood (P<0.05), and spleen (P=0.12). We also analyzed methylation in blood samples from chickens of six recombinant congenic strains (RCS) developed using lines 63 and 72. Methylation variations were detected. The methylation level of the TVB promoter region may have an impact on TVB expression in the hypothalamus (P<0.05). Our data indicate that high promoter CpG methylation levels coincide with low TVB transcription levels in line 72 birds. The relationship between TVB alleles, TVB promoter region DNA methylation, and ALV resistance will be discussed.