Liver-specific expression of a Qa-encoded class I gene is associated with DNA hypomethylation

DNA methylation of two murine major histocompatibility complex (H-2) class I genes was examined in hybridizations to MspI and HpaII chromosomal DNA restriction digests. Q10, which exhibits liver-specific expression, and H-2Kb, a transplantation antigen gene, were examined in liver, spleen, thymus, and cell-line DNAs. Unmethylated Q10 gene sequences were detected only in the liver, whereas the H-2Kb gene was unmethylated in all tissues examined.