Open AccessThe Major Components of the Mouse and Human Genomes
Author(s) -
CUNY Gérard,
SORIANO Philippe,
MACAYA Gabriel,
BERNARDI Giorgio
Publication year - 1981
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1981.tb05227.x
Subject(s) - dna , homogeneous , genome , biology , centrifugation , buoyant density , range (aeronautics) , composition (language) , biophysics , genetics , evolutionary biology , gene , biochemistry , materials science , physics , thermodynamics , linguistics , philosophy , composite material
Main‐band DNA from mammals and birds can be resolved by density gradient centrifugation techniques into three or four families of fragments of different dG + dC contents. These major DNA components are similar in their buoyant densities and relative amounts in all species tested and are observed in DNA preparations ranging in M r from 2 × 106 to over 200 × 106. In the present work, the four major components of mouse and human DNAs were prepared and characterized in several basic properties: relative amounts, dG + dC contents, buoyant densities and compositional heterogeneity. The results obtained lead to the following conclusions: (a) the major DNA components of mouse and man form at least 85% and possibly the totality of the main bands of these DNAs; (b) they have very low compositional heterogeneities over a wide molecular weight range; (c) they derive from very large chromosomal DNA segments of fairly homogeneous base composition, for which the name ‘isochores’ is proposed. A comparison of the compositional heterogeneity of main‐band DNAs from warm‐blooded and cold‐blooded vertebrates confirms our previous conclusion that these DNAs are characterized by a different sequence organization.