The organisation of the long range periodicity calf satellite DNA I variants as revealed by restriction enzyme analysis

The analysis of a large number of restriction sites within the long range periodicity calf satellite DNA I does not reveal a superimposable shorter repeat. Although some restriction sites are present in almost all the 100,000 tandemly arranged copies of the 1460 bp repetition unit, other sites such as Atu CI occur at much lower frequencies. When present they are distributed randomly along the satellite DNA molecules. The missing sites appear to result from random and presumably single base alterations. Digestion with the enzymes Hha I and Kpn I showed another type of variant to exist within the calf satellite DNA I. Unlike Atu CI the distributions of the variants detected by these enzymes are not random and organised on long stretches of satellite DNA. The possible functional significance and evolutionary implication of these results are discussed.