title: Induction of G- and R-banding in human chromosomes by the demethylating agent S-adenosyl-L-homocysteine.
abstract: In this report we describe the procedure of growing human lymphocytes with the demethylating agent S-adenosyl-L-homocysteine (SAH). After this treatment, which is not toxic for cell survival, both R- and G-banding were obtained by new experimental procedures: R-bands have been directly demonstrated with the GC-specific fluorochrome chromomycin A3 without the necessity of any AT-specific counterstaining agent; simultaneous G-banding and active nucleolar organizer regions have been obtained by silver impregnation of chromosomes and subsequent Giemsa staining. These results suggest a possible relationship between local differences in DNA methylation and the determination of the banded chromosome structure.
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Spain.
authors.forename: S F
authors.initials: SF
authors.lastname: De Cabo
authors.forename: C
authors.initials: C
authors.lastname: Sentís
authors.forename: J
authors.initials: J
authors.lastname: Fernández-Piqueras
mesh_terms: D002478:Cells, Cultured; D002871:Chromosome Banding / Q000379:methods*; D004247:DNA / Q000378:metabolism; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008745:Methylation; D012435:S-Adenosylhomocysteine / Q000494:pharmacology*
chemical_list: D004247:DNA; D012435:S-Adenosylhomocysteine; D015254:DNA Modification Methylases