The two component kinetic analysis method. Evidence for two renaturing components in mouse satellite DNA and Dipodomys ordie HS-beta satellite DNA.

Abstract

Eukaryotic DNAs have been shown to exhibit considerable heterogeneity in renaturation properties. A formalism is developed here to deal with kinetic heterogeneity. The simplest case of heterogeneity, two renaturing components, is considered in detail. The two component kinetic analysis method described is tested on a two component, DNA model system and accurately predicts the known properties of the system. This method of analysis is then applied to two simple sequence DNAs, the mouse satellite and HS-β satellite from the kangaroo rat Dipodomys ordii , known to contain sequence heterogeneity. The results resolve the kinetic heterogeneity of each DNA into, a fast and slow renaturing DNA component. Both fast and slow renaturing components of mouse satellite DNA are demonstrated to be second-order. This description of the kinetic heterogeneity of these DNAs is then related to their known properties. The value of 130±25 base-pairs for the fast component complexity of mouse satellite DNA is close to the ancestral kientic complexity and reassociation register of 120 base-pairs determined by Sutton & McCallum (1971) and Southern (1975) . The implications of these findings for the proposed structural models of mouse satellite DNA are then discussed.