Analysis on DNA methylation of various tissues in chicken.

DNA methylation is known to be associated with the transcriptional silencing in eukaryotes. In this study, the genome-wide DNA methylation patterns of CCGG sites were detected with fluorescent-labeled methylation sensitive amplified polymorphism (F-MSAP) in three chicken strains (White Leghorn, White Plymouth Rock, and their F(1) hybrids). The average incidence of DNA methylation was approximately 29.4% in muscle, 27.2% in liver, 27.2% in heart, and 26.1% in kidney, respectively. Also, the significant differences of the DNA methylation levels were found among the different tissues (P < 0.05) or strains (P < 0.05), implying that such differences may be related to gene expression during tissue differentiation, growth, and development though the relation between methylation and gene expression is currently hard to assess.