Sequence-specific microscopic visualization of DNA methylation status at satellite repeats in individual cell nuclei and chromosomes
Scientists from Japan developed methylation-specific fluorescence in situ hybridization (MeFISH) for microscopic visualization of DNA methylation status at specific repeat sequences in individual cells. MeFISH is based on the differential reactivity of 5-methylcytosine and cytosine in target DNA for interstrand complex formation with osmium and bipyridine-containing nucleic acids (ICON). Cell nuclei and chromosomes hybridized with fluorescence-labeled ICON probes for mouse major and minor satellite repeats were treated with osmium for crosslinking. After denaturation, fluorescent signals were retained specifically at satellite [more…]