title: Detection of complex alleles by direct analysis of DNA heteroduplexes.
abstract: DNA molecules derived from three alleles of the HLA-DRB3 locus and differing from each other at several nucleotide sites were denatured and cross-hybridized. Each allelic combination was found to generate a pair of heteroduplexes of different mobility. Their retardation as compared to homoduplexes was proportional to the number of mismatches. In each heteroduplexes pair the component possessing the highest number of Pyr-Pyr oppositions was the most retarded. The results are those predicted by a theoretical model implying a correlation between base-pair opening and bending of the DNA double helix. These observations introduce a new HLA typing method at the genomic level and indicate an experimental approach to the analysis of the superhelical DNA conformation as related to different types of base oppositions.
authors.affiliation: Dipartimento di Biologia Cellulare e dello Sviluppo, Università La Sapienza, Roma, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Sorrentino
authors.forename: C
authors.initials: C
authors.lastname: Iannicola
authors.forename: S
authors.initials: S
authors.lastname: Costanzi
authors.forename: A
authors.initials: A
authors.lastname: Chersi
authors.forename: R
authors.initials: R
authors.lastname: Tosi
mesh_terms: D000483:Alleles; D001483:Base Sequence; D004247:DNA / Q000235:genetics*; D004591:Electrophoresis, Polyacrylamide Gel; D015803:HLA-DR3 Antigen / Q000235:genetics*; D006650:Histocompatibility Testing / Q000379:methods; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009692:Nucleic Acid Heteroduplexes; D009693:Nucleic Acid Hybridization; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D015803:HLA-DR3 Antigen; D009692:Nucleic Acid Heteroduplexes; D004247:DNA