title: [Effect of hyperhybridization of nucleic acids].
abstract: The reasons for the effect of hyperhybridization (HH) of nucleic acids, when the degree of binding of labelled fragments in the heterologous reaction is higher than in the homologous one, are discussed. The object of investigation was DNA of salmon. HH is most demonstrative in hybridization of a DNA fraction which forms thermostable duplexes (Tm greater than or equal to 75 degrees). HH is accounted for by the fact that closely related species and intraspecies forms differ in the percentage of this fraction; therefore if a species with a small content of this fraction in the genome is chosen as a reference species, hybridization of its DNA with that of another species with a high content of the thermostable fraction, exceeds 100% with respect to the homologous fraction). A correction coefficient is suggested allowing comparison between experiments with different reference species. It appears that the genomes of less specialized, as compared with highly specialyzed species, contain more DNA forming thermostable duplexes. It is therefore recommended to use as reference DNA of species, the structure of karyotype and morphologt of which have more in common with the ancestral form.
mesh_terms: D000818:Animals; D004247:DNA; D007621:Karyotyping; D009693:Nucleic Acid Hybridization; D012474:Salmon; D013045:Species Specificity
chemical_list: D004247:DNA
vernacular_title: Ob zffekte gipergibridizatsii nukleionovykh kislot.