Properties of DNA from some malarial parasites

Abstract

The base compositions of DNA from some species of malarial parasite have been estimated by measurement of density in CsCl gradients and of thermal denaturation temperatures. Species from avian (Plasmodium gallinaceum) and rodent (P. bergheiandP. vinckei) hosts – often used as model systems in malarial studies – contain single DNA components with base compositions of about 20% G + C. By contrast, species from primate hosts (P. knowlesiandP. falciparum) contain major DNA components of about 40% G + C and minor ones of about 20% G + C. These differences could be reflexions of markedly different genomes within these two groups of the genusPlasmodium.Apart from differences in base composition, the physico-chemical properties of the main components of DNA from primate and rodent malarial parasites are very similar to those of DNA from mammalian cells. DNA from avian malarial parasites appears to have some unusual properties.One of us (P.I.T.) received financial assistance from the World Health Organization. We thank Dr F. Hawking and Dr J. Williamson for many helpful discussions, Dr W. H. G. Richards, Dr A. Voller and Dr D. C. Warhurst for the provision of some of the strains and Miss Jane Dunnett, Mrs A. C. Gutteridge and Mr T. Scott-Finnigan for technical assistance.