Characteristic features of the sonicated DNA of Agama agama agama L. (Reptilia, Agamidae) on hydroxyapatite columns,...

Hydroxyapatite column chromatography has been used to study some properties of the extensively sheared DNA of the Rainbow lizard, Agama agama agama. Reassociation studies show that the genome has a Cot1/2 of 370. Approximately 15% of the genome is highly repetitive in nature. This repetitive fraction is resolved into thermally stable and less stable fractions. The stable fraction has a base composition of 47% GC, higher than the 40.2% GC for the native DNA. This stable fraction is believed to be of recent origin. Chromatography of the total DNA of the lizard with linear gradients of phosphate buffer containing 1 M urea resolves it into two components which were shown by thermal fractionation, also in the presence of 1 M urea, to vary in base composition. This behaviour may be characteristic of reptilian genomes and may be used as a basis for studying the structural organisation of the reptilian genome.