Imprinting by DNA methylation: from transgenes to endogenous gene sequences.

摘要: A number of transgenes in the mouse show variation methylation and expression phenotypes dependent on parental transmission. It appears that there exist at least two types transgene imprinting; one is retained an essentially homozygous background, while other requires heterozygosity some modifying loci genome observed as differences phenotype reciprocal crosses. For this type imprinting to occur, origin modifier locus itself important, asymmetry may involve specific interactions between egg cytoplasm chromosomes. Based identification 'methylation polymorphism' genome, we also endogenous gene sequences can undergo by DNA methylation.