Segmental amplification in a satellite DNA: restriction enzyme analysis of the major satellite of Macropus rufogriseus.

The 1.708 g/cc satellite DNA of the red necked wallaby is shown to consist of a number of related families of sequences arranged in tandem arrays. Particular families are subpopulations of other families; their distribution supports a model of successive amplification events during the generation of the satellite. In each amplification episode one 2,500 bp unit is multiplied into a tandemly repeated array of that unit (segmental amplification). The 1.708 g/cc sequences can be detected in related kangaroo species in much reduced amount, and with changes to the long order periodicity of the repeat units.