title: [Molecular and cytogenetic approach to the mapping of methylated polymorphic restriction fragments of human rRNA genes].
abstract: Combined restriction with Bam H I and Sal I (or Hpa II) has revealed Bam H I fragment on a non-transcribed spacer of rRNA genes in one out of four individuals under study. Using Ag-staining and hybridization in situ, chromosome 13p+ enriched by inactive rRNA gene copies was found in the given individual. Since Sal I does not restrict methylated sequences and rRNA genes are repressed by methylation, it is concluded that methylated Banm I-restricted rRNA gene fragments of non-transcribed spacer are localized in chromosome 13p+ of the individual in question.
mesh_terms: D002874:Chromosome Mapping; D005796:Genes; D006801:Humans; D008745:Methylation; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D012335:RNA, Ribosomal / Q000235:genetics*
chemical_list: D012335:RNA, Ribosomal
vernacular_title: Molekuliarno-tsitogeneticheskiĭ podkhod k kartirovaniiu metilirovannykh polimorfnykh restriktsionnykh fragmentov genov rRNK